The definitive Android-vs-iPhone matrix: the four verbs (register / locate / be-found-by / detect) defined with engineering precision, then applied across every finding network and every OS — Apple Find My, Samsung SmartThings Find, Google Find My Device, and Tile; the key asymmetries (Android can detect but not own an AirTag; iPhone cannot register a SmartTag; Tile is the only register-on-either-OS option); and the Apple+Google DULT cross-platform detection cooperation that lets each OS alert on the other ecosystem's trackers

9.1 About This Volume

Vols 7 and 8 surveyed the hardware side of the tracker market — the Apple AirTag and Samsung SmartTag family (Vol 7), then Tile, Chipolo, and Pebblebee (Vol 8). Each volume noted where ecosystem lock-in bites. This volume is the synthesis: the definitive, verb-precise, network-by-network, OS-by-OS map of what you can actually do with each tracker depending on which phone you carry.

The engineering problem this volume solves. The word “works with” is dangerously vague in the tracker category. An iPhone user who asks “does this Samsung SmartTag work with my phone?” gets an answer that depends entirely on which verb they have in mind. Detect? Yes — partially. Locate? No. Register? Never. Be-found-by? Only from Galaxy-phone finders, not from their own phone. All four answers are correct and all four are different. Any analysis that collapses these four distinctions into a single “works / doesn’t work” response will mislead the reader. This volume defines the four verbs with precision and then applies them consistently across every major finding network.

What this volume covers. Section §2 defines the four verbs — register, locate, be-found-by, and detect — at the level of specificity needed to fill a matrix cell correctly. Section §3 is the centerpiece: the master 4-verb × network × OS matrix, the primary reference table for this volume. Sections §4 and §5 walk each network from the iPhone’s and Android’s perspective respectively, with the nuances that don’t fit in a table cell. Section §6 is the ASCII decision flow for the most-asked question: “I have an Android — what can I do with this AirTag?” Section §7 covers the DULT cross-platform detection framework — the Apple+Google cooperation that means both OSes can now alert on the other ecosystem’s trackers. Section §8 is the per-OS detection-capability table. Section §9 is the per-tracker “works with” summary. Section §10 covers second-hand and cross-ecosystem gotchas. Section §11 addresses the be-found-by dimension in network-density terms.

What this volume defers. The cryptographic mechanism behind Apple’s Find My network (the rotating P-224 key chain, the ECIES-encrypted finder reports) is Vol 2. UWB Precision Finding (the phone-model requirement, the U1/U2 silicon) is Vol 3. NFC and Lost Mode are Vol 4. The AirTag hardware teardown is Vol 5. The full AirTag operational lifecycle is Vol 6. The SmartTag hardware deep dive is Vol 7; Tile/Chipolo/Pebblebee are Vol 8. Detector apps and dedicated detector hardware (AirGuard, Tracker Detect, commercial BLE sweepers) are Vol 11 — the matrix cells in this volume say “detect: yes” and cross-reference there; they do not review the detection tools themselves. DIY Find My beacons (OpenHaystack, Macless-Haystack) are Vol 10.

Spec-sourced. No tags on the bench as of 2026-06-25. All capability claims are derived from Apple’s published documentation, Google’s Find My Device rollout documentation (April 2024), Samsung’s SmartThings documentation, the Apple+Google DULT specification, and Tile’s published platform support statements.^[Apple Find My network documentation: https://www.apple.com/find-my/. Google Find My Device relaunch: https://blog.google/products/android/find-my-device-network-android/. Apple+Google DULT IETF working group: https://datatracker.ietf.org/wg/dult/about/. Samsung SmartThings Find: https://www.samsung.com/us/smartphones/galaxy-smarttag2/. Tile platform support: https://www.tile.com/help. Where a specific OS build number for a capability is uncertain, the capability is attributed to the OS vendor and hedged accordingly.]

9.2 The Four Verbs: A Precise Vocabulary

Every cross-platform tracker question collapses into one of four distinct operations. The asymmetries in this category live at the verb level. Define them once, use them consistently throughout the volume.

9.2.1 Register

Register means: pair the tracker, bind it to a cloud account, and become the owner of record — the person who can see its location on a map, play its speaker, enable Lost Mode, and ultimately transfer or delete it.

Registration is the gating verb. If you cannot register, none of the other owner-facing operations (locate, share, configure alerts) are available to you. Registration always requires:

A compatible phone platform (the right OS and hardware)
A compatible cloud account (Apple ID, Samsung account, Google account, Tile account)
The tracker’s home network pairing ceremony (the tap-proximity method for AirTag, the SmartThings BLE scan for SmartTag, the Find My accessory flow for Chipolo/Pebblebee Find My models, the Tile app setup for Tile)

Registration is the most locked-down verb in the table. Ecosystem-native trackers (AirTag, SmartTag) have hard OS requirements that cannot be bypassed. Third-party Find My accessory trackers (Chipolo ONE Spot, Pebblebee Clip Find My) inherit Apple’s registration requirement. Only Tile allows registration on either iPhone or Android via the Tile app.

9.2.2 Locate

Locate means: as the registered owner, query your tracker’s current or last-known location — see it on a map, get directions to it, use the UWB precision homing mode to walk to it.

Locate requires that you are already the registered owner. For Apple Find My trackers, locate happens through the Find My app on any Apple device signed into the registering Apple ID (iPhone, iPad, Mac, iCloud.com — all work). For Samsung SmartThings, locate happens through the SmartThings app on the owner’s Galaxy phone. For Google Find My Device, locate happens through the Find My Device app on Android or at android.com/find. For Tile, locate happens through the Tile app on either iOS or Android.

The “multi-device locate” nuance: an AirTag owner who has an iPhone, iPad, and Mac can locate the tag from all three, because all three share the same Apple ID. A SmartTag owner who switches from a Galaxy phone to an iPhone loses locate capability entirely — their account is in the Samsung ecosystem, and the iPhone has no SmartThings Find client. This is the practical consequence of ecosystem-native design.

9.2.3 Be-found-by

Be-found-by means: a tracker’s BLE advertisement is passively detected by a third-party device (not the owner’s phone) which silently encrypts its GPS position and uploads it to the network’s cloud — contributing a location report the owner can later query. The owner’s phone is not involved in this transaction; it may be across the city or in another country. Be-found-by is the heart of the crowdsourced finding model.

This verb belongs to the network architecture, not to the owner’s phone OS. An AirTag is be-found-by Apple’s network regardless of whether the owner has an iPhone or has never touched an Apple device — the finding happens on strangers’ iPhones in the vicinity, not on the owner’s phone. Similarly, a SmartTag is be-found-by Samsung Galaxy phones near the lost tag, independent of the owner’s device.

The density implications are significant and are the subject of §11. A tracker be-found-by a small network (Tile’s proprietary network, Samsung’s Galaxy install base in North America) gets fewer reports per hour than one be-found-by Apple’s ~1 billion-device Find My network. The be-found-by dimension is the most underappreciated column in the cross-platform comparison.

9.2.4 Detect

Detect means: an OS or app identifies that an unknown tracker is traveling with a person who is not its registered owner — and alerts that person. Detect is the anti-stalking verb. It is the operational inverse of the other three: while register/locate/be-found-by are things the owner does, detect is what an unwitting third party’s device does on their behalf.

Three detection mechanisms appear in this volume’s matrix:

OS-native alerts — built into iOS and Android without any app required. iOS has provided “Found Moving With You” alerts since iOS 14.5. Android added native unknown-tracker alerts as part of the DULT rollout (see §7).
Dedicated apps — Apple’s Tracker Detect (Android, manual scan), AirGuard (TU Darmstadt, iOS and Android, passive monitoring), and equivalent third-party scanning tools. Coverage of these apps is Vol 11; they appear here only as a matrix entry.
NFC-tap read — distinct from detection alerts: a person who physically finds an AirTag can tap it with any NFC phone (iPhone or Android) to open found.apple.com and read the serial number and Lost Mode contact information (if enabled). This is not a tracking-alert mechanism; it is a manual identification step. Covered in Vol 4 §2 and referenced in the matrix cells below.

Detection capability by OS is one of the key asymmetries in this category: iOS can detect foreign-ecosystem trackers (SmartTag, Google-network tags, Tile) via DULT-derived alerts; Android can detect AirTags via DULT and via Tracker Detect / AirGuard. Both OSes gaining cross-ecosystem detect capability is the headline development of the DULT cooperation (§7).

9.2.5 Why the verb distinctions matter — the asymmetry lives here

The four verbs carve up the capability space into regions that confuse buyers, reviewers, and even support documentation writers. The most important asymmetry to internalize before reading the matrix:

Android can detect an AirTag but cannot register or locate one.

This sounds paradoxical. The same phone that raises an anti-stalking alert when an AirTag is following it cannot be used to own or find an AirTag. The resolution: detect operates on the network signaling side (the BLE advertisement’s Find My service data is visible to any BLE-capable phone, and the DULT framework tells Android what to do with it), while register and locate operate on the account and crypto side (the Apple ID binding and the ECIES-encrypted location reports that only Apple’s infrastructure can resolve). These are independent mechanisms and independent capabilities.

A parallel asymmetry runs the other direction:

An iPhone cannot register a SmartTag or a Google-network tag.

An iPhone user can detect an unknown SmartTag traveling with them (via DULT alerts on modern iOS) but cannot own one, cannot see one on a map, and cannot use SmartThings Find at all. The iPhone’s locate and register verbs are constrained to Apple Find My network accessories only.

9.3 The Master Matrix: Four Verbs × Five Networks × Two OSes

9.3.1 Reading the matrix

The diagram below shows the phone-to-network ownership access picture at a glance before the full table. A solid line (→) means the phone OS can register and locate on that network; a dashed line (—) means detect-only access (DULT alert but no ownership); no line means no access in any direction.

   Phone → Finding network ownership access map
   ═════════════════════════════════════════════════════════════════════

   iPhone ──────────────────────────────┐
   (Apple ID)                           ▼
                              ┌─────────────────────┐
                              │   Apple Find My      │ ◄─── ~1B+ Apple devices
                              │   (AirTag, Chipolo   │       participate as finders
                              │    ONE Spot, Pebblebee│       (auto-enrolled)
                              │    Find My)          │
                              └─────────────────────┘
                                         ▲
   iPhone ··· (DULT detect only) ········┘
   iPhone ··· (DULT detect only) ··········┐
                                           ▼
   Galaxy ──────────────────────────────┐  ┌─────────────────────┐
   Android                              └─►│  SmartThings Find   │ ◄─── Galaxy phones
   (Samsung account)                       │  (SmartTag family)  │       only as finders
                                           └─────────────────────┘
   Non-Samsung Android ··· (DULT) ·········►  (no owner access)

   Any Android ─────────────────────────┐
   (Google account)                     ▼
                              ┌─────────────────────┐
                              │  Google Find My      │ ◄─── Android phones
                              │  Device network      │       (opt-in finders)
                              │  (Chipolo POINT,     │
                              │   Pebblebee Google)  │
                              └─────────────────────┘
                                         ▲
   iPhone ··· (DULT detect only) ········┘

   iPhone ──────────────────────────────┐
   or any Android                       │
   (Tile account)                       ▼
                              ┌─────────────────────┐
                              │  Tile Network        │ ◄─── Tile-app phones
                              │  + Amazon Sidewalk   │       + Sidewalk hardware
                              └─────────────────────┘

   Legend: ─── full owner access (register + locate + be-found-by)
           ··· detect-only (DULT alert; no register/locate)
           ◄── be-found-by: these phone types act as anonymous finders

The matrix below has finding networks / tracker families as rows and four verbs × two OS columns (iPhone and Android) as columns. Each cell is one of:

Yes — fully supported on all relevant devices in that OS
No — not supported; attempting it fails or the capability does not exist
Partial / qualified — supported with conditions (specific phone model, specific app, specific account type); the condition is stated
Galaxy only — supported on Samsung Galaxy Android phones but not on non-Samsung Android (Pixel, OnePlus, etc.)
Any NFC phone — the NFC-tap-to-read case, which works on any Android or iPhone with NFC

Five networks are represented as rows:

Apple Find My (AirTag + Chipolo ONE Spot / CARD Spot + Pebblebee Find My variants)
Samsung SmartThings Find (SmartTag / SmartTag+ / SmartTag2)
Google Find My Device (Android FMD, relaunched April 2024; Chipolo POINT / CARD POINT + Pebblebee Google variants)
Tile (Tile Mate / Pro / Slim / Sticker — proprietary Tile network + Amazon Sidewalk)
Chipolo / Pebblebee cross-network (the per-SKU choice at purchase)

The Chipolo/Pebblebee row is a convenience row to capture the “which SKU you bought determines which network you’re in” point; the Find My and Google FMD cells above already cover the capabilities once you know which SKU.

9.3.2 The centerpiece table

Table 1 — 3.2 The centerpiece table

Tracker / Network	Register (iPhone)	Locate (iPhone)	Be-found-by (iPhone)	Detect (iPhone)	Register (Android)	Locate (Android)	Be-found-by (Android)	Detect (Android)
Apple Find My (AirTag, Chipolo ONE Spot / CARD Spot, Pebblebee Find My)	Yes — iPhone + Apple ID required	Yes — Find My app / iCloud.com	Yes — all iPhone/iPad/Mac running iOS 14.5+ participate as finders	Yes — iOS “Found Moving With You” native alert (since iOS 14.5); AirGuard (iOS app, passive monitoring) also available	No — Android cannot register; no Apple ID binding path	No — no Find My client on Android; cannot decrypt location reports	Yes — but via iPhone finders near the tag; Android phones do NOT act as Find My finders	Yes (DULT + apps) — Android native unknown-tracker alerts; Tracker Detect (manual); AirGuard (passive); NFC-tap to read serial
Samsung SmartThings Find (SmartTag / SmartTag+ / SmartTag2)	No — requires Galaxy phone + Samsung account	No — no SmartThings Find client for iOS	No — iPhones do not participate in SmartThings Find; Galaxy phones only	Yes (DULT partial) — iOS native DULT-derived alert for traveling unknown tags; no SmartThings app UX on iPhone	Galaxy only — requires Samsung Galaxy phone + Samsung account; non-Samsung Android cannot register	Galaxy only — SmartThings app on Galaxy phone only	Galaxy only — only Samsung Galaxy phones with SmartThings Find enabled act as finders	Yes (Galaxy native) — SmartThings Unknown Tag search; DULT alerts on other Android via OS alert
Google Find My Device (Chipolo POINT / CARD POINT, Pebblebee Google, Google-network tags; network relaunched April 2024)	No — Android (Google account) required to register	No — Find My Device app is Android-only; no iOS client	No — iPhones do not participate in the Google FMD finder network; Android phones only as finders (Register(iPhone)=No makes this moot)	Yes (DULT partial) — iOS DULT-derived alert for unknown traveling tags; no native Google FMD UX	Yes — Android 9+ with Google account; Google Find My Device app	Yes — Find My Device app (Android) or android.com/find	Yes — Android phones with Google Play Services participate as finders (opt-in; see §11)	Yes — Android native unknown-tracker alerts; Find My Device app
Tile (Mate / Pro / Slim / Sticker; Life360 cloud + Amazon Sidewalk)	Yes — Tile app on iPhone; cross-platform registration	Yes — Tile app on iPhone	Partial — iPhones with Tile app installed act as finders; Sidewalk (Amazon Echo/Ring) also contributes	Yes — Tile Scan-and-Secure on iPhone; Tile DULT alerts	Yes — Tile app on any Android; cross-platform registration	Yes — Tile app on any Android	Partial — Android phones with Tile app installed act as finders; Sidewalk also contributes	Yes — Tile Scan-and-Secure on Android; DULT alerts
Chipolo / Pebblebee (per-SKU network choice)	Find My SKU: Yes (iPhone + Apple ID) · Google SKU: No	Find My SKU: Yes · Google SKU: No	Find My SKU: Yes (iPhone finders) · Google SKU: Partial (Android finders only)	Both SKUs: Yes — DULT alerts on iOS	Find My SKU: No · Google SKU: Yes (Android + Google account)	Find My SKU: No · Google SKU: Yes	Find My SKU: Yes (iPhone finders benefit owner) · Google SKU: Yes (Android finders)	Both SKUs: Yes — DULT alerts on Android

9.4 iPhone — Network by Network

9.4.1 Apple Find My

An iPhone is the native home of the Apple Find My network. Every capability is available with an iPhone and a valid Apple ID. The full lifecycle — pairing, renaming, Find My Items tab, Precision Finding (iPhone 11+, U1/U2), Directions, Notify When Left Behind, Lost Mode, Sharing (iOS 17+), and battery-replacement workflow — is Vol 6. The hardware teardown including the nRF52832, Apple U1, and NXP NT3H2111 is Vol 5.

For the purposes of this volume’s matrix, the iPhone’s four verbs against Apple Find My are:

Register: Yes — iPhone + iOS 14.5+ + Apple ID + 2FA + internet at pairing time. iPad can manage but cannot complete initial pairing proximity ceremony.
Locate: Yes — Find My app, all iOS 14.5+ devices on the same Apple ID, and iCloud.com.
Be-found-by: Yes — the iPhone is the primary finding device for the entire ~1 billion-device network. Every unlocked iPhone in the vicinity of a separated AirTag contributes an encrypted location report.
Detect: Yes — iOS 14.5+ provides the “Found Moving With You” / “Unknown Accessory Found Moving With You” alert natively, without any app installed. The alert fires when an unrecognized tag is observed traveling with the iPhone across time and distance (the separated-state / anti-stalking beaconing logic is Vol 4 §6).

Third-party Find My accessories (Chipolo ONE Spot, CARD Spot; Pebblebee Clip Find My, Tag Find My, Card Find My) inherit exactly the same capability profile as an AirTag against an iPhone. They are registered through the Find My app as “items,” use the same BLE advertising protocol (Vol 2), participate in the same ~1 billion-device finding network, and trigger the same iOS detection alerts. The difference is hardware only — no UWB on Chipolo/Pebblebee, and different form factors (card, key fob). See Vol 8 §4.3, §5 for the product details.

9.4.2 Samsung SmartThings Find — the Galaxy-only wall

An iPhone cannot register, locate, or participate in SmartThings Find. There is no SmartThings Find client for iOS, no path to connect a SmartTag to an Apple ID, and no mechanism by which iPhones contribute as finders to the SmartThings Find network. The SmartTag is invisible to the iPhone in every owner-facing role.

This is the hardest wall in the cross-platform landscape. A buyer who walks into a store, picks up a Samsung SmartTag2 because the ring form factor or the programmable button appeals to them, and goes home to an iPhone will discover that the tag is entirely unusable to them. The Samsung packaging does not prominently feature an “iPhone users: this will not work for you” warning, making this the most common cross-ecosystem purchase mistake in the tracker category.

What an iPhone can do with a SmartTag, in the limited cross-platform direction:

Detect (partial, via DULT): A SmartTag that is separated from its owner and has been traveling with an iPhone user for a sustained period will trigger a DULT-derived alert on modern iOS. The alert does not come from SmartThings — it comes from iOS’s own DULT-compliant tracker detection layer, which recognizes the SmartTag’s BLE advertising format as a trackable accessory type. The alert experience is similar to the AirTag “Found Moving With You” UX but is implemented via the DULT interoperability framework rather than the native Find My system. The iPhone user can then take the tag to a Samsung Galaxy phone user to have it identified, or use an NFC phone to tap it (the SmartTag2 has NFC; original SmartTag models do not).

Detect is the only SmartThings verb an iPhone user gets. Register, locate, and be-found-by are zero.

9.4.3 Google Find My Device

The Google Find My Device network (relaunched with significant improvements in April 2024^[Google, “A new era for Find My Device on Android,” Google Blog, May 2023, with full rollout April 2024. https://blog.google/products/android/find-my-device-network-android/. The relaunched network uses end-to-end encryption for location reports and requires opt-in by Android users.]) is an Android-ecosystem network. iPhones do not participate in either direction for the owner-facing verbs:

Register: No. Registration requires an Android device and a Google account. There is no iOS path.
Locate: No. The Find My Device app is Android-only; the web client at android.com/find is for Android devices (phones, tablets, earbuds) registered to a Google account — not for third-party tracker accessories in the context of an iPhone owner.
Be-found-by: No. The Google FMD crowdsourced network uses Android phones running Google Play Services as finders. iPhones do not participate.
Detect: Yes (partial, DULT). An iPhone running a DULT-compliant OS version will raise an alert if a Google FMD-network tag (e.g., a Chipolo POINT or Pebblebee Google variant) is observed traveling with it. This is the same cross-ecosystem DULT mechanism described in §7.

The practical scenario: if a Chipolo POINT (Google FMD network) is placed in an iPhone user’s bag without their knowledge, their iPhone can raise a DULT-derived tracking alert — they just cannot use their iPhone to identify or locate the specific tag through Google’s system. They would need to scan the tag’s NFC (if present) or use a separate Android device.

9.4.4 Tile

Tile is the one network where the iPhone is a full first-class citizen:

Register: Yes — Tile app (iOS) on an iPhone, Tile account (email-based; no Apple ID required, though the app installs from the App Store). Any iPhone running a reasonably current iOS can register any Tile product.
Locate: Yes — Tile app on the iPhone shows last-known location, triggers the speaker (BLE range), and shows the proximity signal-strength indicator.
Be-found-by: Partial — iPhones with the Tile app installed contribute as finders. This is a significant constraint: unlike Find My (where every iPhone participates automatically), only the subset of iPhones with the Tile app installed will detect a separated Tile tag in the background. That subset is smaller than the Find My participant pool by a substantial margin; see §11 for the density comparison. Amazon Sidewalk devices (Echo, Ring) also contribute as finders independently of phone platform.
Detect: Yes — Tile’s Scan-and-Secure feature (in the Tile app, iOS) allows a user to manually scan for nearby Tile devices to check for unknown tags. Tile also participates in DULT for automatic alerts where the OS provides them.

9.4.5 Chipolo and Pebblebee

Chipolo and Pebblebee both offer parallel SKU lines — one attaches to Apple Find My, one to Google Find My Device. The iPhone’s capability follows directly from the network:

Chipolo ONE Spot / CARD Spot (Find My SKU): Full iPhone support — register, locate, be-found-by, detect. Equivalent to an AirTag from the iPhone’s perspective (no UWB on the Chipolo hardware, but Find My network participation is identical). See Vol 8 §4.3.
Chipolo POINT / CARD POINT (Google FMD SKU): Register: No. Locate: No. Be-found-by: No (Android finders only). Detect: Yes (DULT alert on iOS if the tag travels with the iPhone user). The Find My and Google SKUs look nearly identical physically; verify the packaging before purchasing.
Pebblebee Clip/Tag/Card (Find My variants): Full iPhone support — identical to Chipolo ONE Spot.
Pebblebee Clip/Tag/Card (Google FMD variants): No register/locate/be-found-by on iPhone; DULT detect only.

The Chipolo/Pebblebee per-SKU network choice at purchase is irreversible for the tag’s lifetime. There is no firmware update, no app reconfiguration, and no account-transfer that moves a Find My SKU to Google FMD or vice versa. The network choice is baked into the hardware: the Find My SKU runs Apple’s offline-finding cryptography (Vol 2 §4); the Google SKU runs Google’s equivalent. A buyer who picks the wrong SKU for their phone has a tag that is permanently wrong for their use case. This is the “one-network-per-SKU trap” covered in Vol 8 §8.

9.5 Android — Network by Network

9.5.1 Apple Find My — the detect-but-not-register asymmetry

This is the most important asymmetry in the cross-platform tracker landscape, and it is worth stating plainly at the top of this section before the per-verb walkthrough.

An Android phone can detect an AirTag traveling with it — but cannot register one, cannot locate one on a map, and is invisible to the owner’s Find My queries.

The mechanics behind each cell:

Register: No. The AirTag pairing ceremony requires an iPhone running iOS 14.5+, signed into an Apple ID with two-factor authentication. The cryptographic exchange at pairing (the NIST P-224 master keypair generation and the Apple ID binding — Vol 2 §4.2) is specific to Apple’s BLE connection layer and Apple’s iCloud infrastructure. There is no Android equivalent and no supported workaround. OpenHaystack / Macless-Haystack (Vol 10) can impersonate a Find My beacon but cannot register an existing AirTag to an Android account.
Locate: No. The Find My network’s location reports are ECIES-encrypted ciphertext that only the registered owner’s Apple ID can decrypt (Vol 2 §6). Android has no access to Apple’s iCloud infrastructure as an authenticated Find My participant. An Android user who somehow obtained an unregistered AirTag would have no mechanism to see its location.
Be-found-by: Yes — and this is a critical and often-missed point. The be-found-by verb depends on which phones are near the lost tag, not on the owner’s phone. An AirTag owned by an iPhone user is be-found-by iPhones near where it is lost. Android phones do not participate in Apple’s Find My finder network — they do not detect and report AirTag BLE advertisements to Apple’s servers. So while the owner’s phone has no bearing on this cell, the answer is “Yes” only in the sense that the tag will be found by iPhone passers-by (the ~1 billion-device Find My network); Android passers-by contribute nothing. An Android user who owns an AirTag — if such a thing were possible — would have a tag that gets found by iPhones near the lost item, but the owner could not retrieve those reports. Since register is blocked, this scenario is moot, but the architecture matters: the be-found-by network is the iPhone ecosystem, entirely.
Detect (AirTag): Yes — this is the one verb Android gets against Apple Find My. Android’s native unknown-tracker alerts (DULT-derived, added to Android as part of the Apple+Google DULT cooperation) will raise an alert when an unrecognized AirTag has been traveling with the Android user for a sustained period. The Tracker Detect app (published by Apple for Android) performs a manual BLE scan to identify Find My–format advertisers in the immediate vicinity. The AirGuard app (TU Darmstadt) performs passive continuous monitoring. Any Android phone with NFC can also tap a physically found AirTag to open found.apple.com and read its serial number and Lost Mode contact information (Vol 4 §2.4). Detect is thorough on Android, even though register and locate are completely blocked.

The detect-but-not-register asymmetry is not an accident or an oversight — it is a deliberate architecture. Apple designed Find My’s registration and location-report cryptography to be Apple-ID–bound and Apple-infrastructure–only. The anti-stalking detection, however, is in the victim’s interest and therefore designed to be as broad as possible — including non-Apple devices. DULT formalizes this cross-platform detection intent as an industry standard. The asymmetry is the correct outcome: detection should be universal; ownership should be authenticated.

9.5.2 Samsung SmartThings Find — Galaxy phones vs other Android

SmartThings Find introduces a sub-split within Android: Galaxy phones vs all other Android phones (Pixel, OnePlus, Motorola, Sony, etc.).

Register (Galaxy Android): Yes — Samsung Galaxy phone + Samsung account + SmartThings app. The full registration ceremony (Vol 7 §6.2) is available to Galaxy phone users.
Register (non-Samsung Android): No. The SmartThings app can be installed on a non-Samsung Android phone for other SmartThings functions, but SmartTag registration requires a Galaxy phone. Samsung’s documentation and support pages specify a Galaxy smartphone as the hardware requirement; the SmartThings app on a Pixel or similar device does not offer SmartTag registration.
Locate (Galaxy): Yes — SmartThings app on the Galaxy phone; last-known location on the SmartThings map.
Locate (non-Samsung Android): No.
Be-found-by: Galaxy phones only. The SmartThings Find finder network consists of Samsung Galaxy devices with SmartThings Find enabled. Non-Samsung Android phones do not participate.
Detect (Galaxy): Yes — SmartThings app provides an “Unknown Tag Search” function that scans for SmartTag-format BLE advertisers not associated with the user’s account. DULT alerts also apply.
Detect (non-Samsung Android): Yes (DULT) — non-Samsung Android phones receive DULT-derived unknown-tracker alerts for SmartTag BLE signals observed traveling with them, via the OS-native alert mechanism. They do not receive SmartThings-app alerts, but the core anti-stalking alert fires.

The SmartTag Galaxy-only catch: buying a SmartTag to use with a Pixel is buying a non-functional tracker. The register and locate verbs are both zero on non-Samsung Android. Even within the Samsung ecosystem, the SmartTag’s be-found-by network is substantially smaller in North America and Europe than Apple’s Find My network — the regional density picture is §11. A non-Galaxy Android user who wants ecosystem-native tracking is in a better position buying a Tile (cross-platform app) or a Chipolo POINT / Pebblebee Google FMD variant, both of which register and locate on any Android with a Google account.

9.5.3 Google Find My Device

The Google Find My Device network relaunched in April 2024 with end-to-end encrypted crowdsourced finding — broadly analogous to Apple’s Find My architecture. This is the Android-native equivalent, and Android phones are the full first-class citizens here.

Register: Yes — any Android phone running Android 9 (Pie) or later with a Google account. The Find My Device app (available on Google Play, also pre-installed on many Android devices) handles tag pairing for compatible accessories (Chipolo POINT, CARD POINT; Pebblebee Google variants) and is also used to locate Android devices, earbuds, and other Google-tagged accessories.
Locate: Yes — Find My Device app on Android, or the web interface at android.com/find. Location reports are end-to-end encrypted; only the owner’s Google account can decrypt them.
Be-found-by: Yes — Android phones running Google Play Services with Find My Device participation enabled contribute as anonymous finders. The opt-in nature of Android FMD participation (unlike iOS, which auto-enrolls most devices) means the effective finder pool depends on the regional opt-in rate; see §11.
Detect: Yes — Android native unknown-tracker alerts apply to Google FMD–network tags; the Find My Device app also provides identification.

The Google FMD network is substantially newer than Apple’s Find My and Samsung’s SmartThings Find. The April 2024 relaunch introduced end-to-end encrypted finding for accessories — the architecture that makes it comparable to Find My’s privacy model. The effective network size relative to Find My is discussed in §11; it is growing and may ultimately approach Find My density in Android-dominant markets, but as of 2026 the gap is likely significant in most regions.

9.5.4 Tile

Tile is the only network where Android gets complete parity with iPhone:

Register: Yes — Tile app on Android (Google Play), Tile account. No phone-brand requirement; any Android phone with a reasonably current OS version works.
Locate: Yes — Tile app on Android shows last-known location, controls the speaker, and shows the proximity indicator.
Be-found-by: Partial — Android phones with the Tile app installed contribute as finders, in addition to iOS phones with the Tile app and Amazon Sidewalk devices. The participation constraint (app-installed only) applies equally to Android and iOS.
Detect: Yes — Tile Scan-and-Secure is available in the Tile app on Android; DULT alerts apply.

This full parity is Tile’s core cross-platform value proposition. An Android user who wants to find lost items and doesn’t want to be limited to the Google FMD ecosystem (or doesn’t own a Galaxy) can register and fully operate Tile tags. The tradeoff is network density (§11) and no UWB.

9.5.5 Chipolo and Pebblebee

Same pattern as the iPhone section, but with the Find My / Google FMD roles swapped:

Chipolo POINT / CARD POINT (Google FMD SKU): Full Android support — register (any Android + Google account), locate (Find My Device app), be-found-by (Android FMD network), detect (Android native alerts).
Chipolo ONE Spot / CARD Spot (Find My SKU): Register: No (requires iPhone + Apple ID). Locate: No. Be-found-by: No (iPhones as finders, inaccessible to an Android owner). Detect: Yes (DULT alert on Android if the tag travels with the Android user).
Pebblebee Google variants: Full Android support — identical to Chipolo POINT.
Pebblebee Find My variants: No register/locate/be-found-by on Android; DULT detect only.

The rechargeable battery (USB-C on Pebblebee, as opposed to coin-cell on Chipolo — Vol 8 §5.3) does not affect the network membership or the cross-platform verb picture; it is a hardware differentiator within each SKU line.

9.6 The Android + AirTag Decision Flow

The single most-asked cross-platform question in the tracker category: “I have an Android phone — what can I do with this AirTag I found / was given / am thinking of buying?” The answer has four distinct paths.

"I have an Android phone. What can I do with this AirTag?"
══════════════════════════════════════════════════════════

   Q1: Can I register (pair and own) this AirTag?
               │
               ▼
          ┌─────────────────────────────────────────────┐
          │  NO — unconditionally.                       │
          │  Registration requires an iPhone (iOS 14.5+) │
          │  + Apple ID + 2FA.                           │
          │  No Android path exists.                     │
          │  OpenHaystack / Macless-Haystack (Vol 10)    │
          │  cannot register an existing AirTag.         │
          └─────────────────────────────────────────────┘
               │
               ▼
   Q2: Can I locate (see on a map) this AirTag?
               │
               ▼
          ┌─────────────────────────────────────────────┐
          │  NO — unconditionally.                       │
          │  No Find My client on Android.               │
          │  Location reports are Apple-ID–encrypted     │
          │  ciphertext (Vol 2 §6); Android has no       │
          │  decryption path.                            │
          └─────────────────────────────────────────────┘
               │
               ▼
   Q3: Can I detect an AirTag that is traveling with me
       without my knowledge?
               │
               ▼
          ┌──────────────────────────────────────────────────────┐
          │  YES — three detection methods available:            │
          │                                                      │
          │  (a) Android OS native alert (DULT-compliant):       │
          │      appears automatically if an unknown AirTag      │
          │      has been traveling with you; no app needed.     │
          │      Introduced as part of the Apple+Google DULT     │
          │      cooperation (§7). Exact Android version         │
          │      threshold: attributed to Google's DULT rollout; │
          │      hedge applies (see §7.3 for details).           │
          │                                                      │
          │  (b) Apple Tracker Detect app (Play Store):          │
          │      manual BLE scan for Find My–format beacons      │
          │      in your vicinity. Run on-demand.                │
          │      Covered in depth in Vol 11.                     │
          │                                                      │
          │  (c) AirGuard app (TU Darmstadt, Play Store):        │
          │      passive continuous monitoring; logs AirTags     │
          │      that consistently appear near your phone.       │
          │      Works in the background. Vol 11.                │
          └──────────────────────────────────────────────────────┘
               │
               ▼
   Q4: Can I NFC-tap a physically found AirTag
       to identify it?
               │
               ▼
          ┌──────────────────────────────────────────────────────┐
          │  YES — any Android phone with NFC.                   │
          │  Tap the AirTag (white plastic side toward phone).   │
          │  The phone's browser opens found.apple.com.          │
          │  Shows: serial number.                               │
          │  Shows (if Lost Mode ON): owner's contact info       │
          │  and custom message.                                 │
          │  Shows (if Lost Mode OFF): "linked to an Apple       │
          │  Account" notice; no owner contact.                  │
          │  The NXP NT3H2111 NDEF stores only a URI to          │
          │  found.apple.com; the contact info lives server-side │
          │  (Vol 4 §2.3). No app needed; standard NFC web-push. │
          └──────────────────────────────────────────────────────┘
               │
               ▼
   Summary for the Android user:
   ┌──────────────────────────────────────────────────────────────┐
   │  REGISTER:    NO                                             │
   │  LOCATE:      NO                                             │
   │  BE-FOUND-BY: YES (as a passive bystander — your phone      │
   │               does NOT contribute to Find My; the tag is    │
   │               found by iPhones near it, not by you)         │
   │  DETECT:      YES (OS alert + Tracker Detect + AirGuard)    │
   │  NFC-READ:    YES (any Android with NFC)                    │
   │                                                             │
   │  If you want an item tracker that registers on Android,     │
   │  choose: Tile (any Android), Chipolo POINT (Google FMD),    │
   │  Pebblebee Google variant, or if you have a Galaxy phone,   │
   │  Samsung SmartTag (Galaxy only). Not AirTag.                │
   └──────────────────────────────────────────────────────────────┘

9.7 Cross-Platform Detection: The DULT Framework

9.7.1 What DULT is and why it exists

DULT stands for Detecting Unwanted Location Trackers — an IETF working group specification developed jointly by Apple and Google to standardize how phones detect and alert users to unwanted BLE tracking accessories, regardless of which ecosystem manufactured the tracker.^[Apple+Google DULT specification: IETF working group “dult” — https://datatracker.ietf.org/wg/dult/about/. The specification defines how tracking accessories must behave when separated from their owner (the “separated accessory” beaconing behavior) and how devices that detect such accessories should alert users. Both Apple and Google have made public commitments to implement DULT in their respective OSes.]

The DULT origin story is Vol 4 §7 — read there for the full regulatory and industry-pressure context that produced the spec. The summary for this volume: Apple’s Find My anti-stalking system (the “Found Moving With You” iOS alert) was iOS-only, and Android users had no systematic protection against AirTag-facilitated stalking. Google’s Android had no comparable built-in alert. Simultaneously, Apple’s Tracker Detect Android app was manual-only and required users to already suspect they were being tracked. Investigative reporting, advocacy groups, and regulatory pressure in multiple jurisdictions (US, EU, UK) converged on the same requirement: both platforms needed automatic, cross-ecosystem tracking alerts. DULT is the specification that coordinates what that looks like.

DULT defines two things at the protocol level:

How a separated tracker must behave — specifically, the advertising format and timing that a tracker must use when it has been separated from its owner for more than a specified duration. This “separated accessory advertising” is the BLE signal that DULT-compliant phones watch for.
How a phone must alert users — when the phone detects a DULT-format separated-accessory advertisement consistently following it over time, it must raise a user-visible alert.

The result: a Samsung SmartTag that has been away from its owner for long enough and that is following an iPhone user will trigger an iOS DULT alert. An AirTag following an Android user will trigger an Android DULT alert. The alert origin is the phone’s OS, not the tracker manufacturer’s app.

9.7.2 iOS native detection — “Found Moving With You”

iOS has offered built-in AirTag detection since iOS 14.5 under the label “Item Found Moving With You” or “Unknown Accessory Found Moving With You” (the exact label varies by iOS version). The mechanism: iOS runs a background BLE scan for Find My–format separated-state advertisements; when a consistent signal is observed traveling with the iPhone over a time threshold and geographic distance, the alert fires.

iOS 14.5’s initial detection was AirTag-specific (it understood Apple’s separated-state advertising format). DULT compliance extends this to cover accessory types from other manufacturers that implement the DULT separated-accessory advertising format. The combined iOS detection surface post-DULT:

AirTag (Apple) — native, pre-DULT, since iOS 14.5
Third-party Find My accessories (Chipolo ONE Spot, Pebblebee Find My) — covered by the same iOS Find My detection layer
SmartTag (Samsung) — DULT-derived alert when Samsung implements DULT
Google FMD accessories (Chipolo POINT, Pebblebee Google) — DULT-derived alert
Tile — DULT-derived alert

The exact DULT rollout timeline and the iOS version at which cross-ecosystem alerts for each foreign tracker type became available is attributed to Apple’s release notes and the DULT working group’s public materials; specific iOS build numbers are not asserted here as the rollout was phased and ongoing through 2024–2025. The engineering principle is clear: iOS can detect the others; the timing of each manufacturer’s DULT implementation determines when each foreign-brand alert becomes active.

9.7.3 Android native detection — unknown tracker alerts

Android’s native unknown-tracker alerts were announced as part of the Apple+Google DULT joint rollout and began appearing in Android starting in 2024. The mechanism is the Android OS’s own BLE scanning layer — similar in architecture to iOS’s implementation — watching for DULT-format separated-accessory advertisements and raising a notification when one is detected traveling with the Android user.

The specific Android version at which native unknown-tracker alerts for each tracker type became available is attributed to Google’s Android release materials and the DULT working group; specific build numbers are not asserted here as the rollout was phased and device-manufacturer-dependent (Google Pixel devices typically receive Google updates earlier than Samsung Galaxy or other OEM devices, for example). What is unambiguous from Google’s public announcements:

AirTag detection on Android via DULT is supported by Google’s DULT implementation
SmartTag detection on Android is similarly supported once Samsung implements DULT in the SmartTag firmware
Google FMD accessories are natively covered by Android’s own FMD alerts
Tile detection is covered by DULT when Tile implements the separated-accessory advertising format

Android detection supplements rather than replaces the explicit detection apps: Apple’s Tracker Detect (manual BLE scan for Find My–format beacons, Play Store) and AirGuard (passive continuous monitoring, TU Darmstadt, Play Store) remain useful for users who want more granular control or historical logging. Vol 11 covers those tools in detail.

9.7.4 The DULT cooperation point — each OS can now alert on the other’s trackers

The DULT framework is the single most important cross-platform development in tracker detection. Prior to DULT, the iOS + AirTag combination was effectively a one-ecosystem stalking tool: Android users had no automatic protection, and iPhone users had no automatic protection against non-AirTag trackers (SmartTags, Tile). DULT closes both gaps simultaneously: iOS alerts on SmartTags, Google-FMD tags, and Tile; Android alerts on AirTags, SmartTags, and Google-FMD tags.

The critical observation for the matrix: DULT enables cross-ecosystem detection without enabling cross-ecosystem ownership. An Android user whose DULT alert fires for a traveling AirTag can identify the tag (NFC tap for the serial number, Tracker Detect for the BLE identifier) and contact the owner if Lost Mode is on — but the Android user cannot register the AirTag, cannot see it on a map, and cannot use Find My to investigate further. Detection and ownership remain decoupled by design, and that decoupling is correct: the victim of unwanted tracking should be able to detect and act, regardless of which phone they carry; the anti-theft and anti-stalking properties of account binding should remain intact.

The cooperative framing matters for this volume because several sources describe the cross-platform situation as “Apple and Android fighting over tracking territory.” The accurate framing is the opposite: Apple and Google collaborated on a joint specification to ensure that both user populations are protected from both ecosystems’ trackers. This is unusual inter-OS cooperation driven by a genuine safety imperative and regulatory pressure, not by technical necessity or market forces.

9.8 Per-OS Detection Capability Table

Detection capability is the one verb where both OSes get broad coverage. The table below maps each tracker type against the detection methods available on each OS.

Table 2 — 8. Per-OS Detection Capability Table

Tracker type	iOS detection method	iOS detection status	Android detection method	Android detection status
Apple AirTag	iOS native “Found Moving With You” (since iOS 14.5); AirGuard (iOS app, Vol 11); NFC-tap to ID	Yes — automatic, no app needed	Android OS native DULT alert; Apple Tracker Detect app (manual, Play Store); AirGuard (passive, Play Store); NFC-tap to ID	Yes — automatic via DULT + apps
Samsung SmartTag / SmartTag2	iOS DULT-derived alert; NFC-tap (SmartTag2 only — original SmartTag has no NFC)	Yes — DULT alert; NFC on SmartTag2 only	Android OS DULT alert; SmartThings “Unknown Tag Search” (Galaxy phones only); NFC-tap (SmartTag2 only)	**Yes — DULT + SmartThings (Galaxy)
Google FMD accessories (Chipolo POINT, Pebblebee Google)	iOS DULT-derived alert	Yes — DULT alert	Android OS DULT alert; Find My Device app identification	Yes — native
Tile (Mate / Pro / Slim / Sticker)	iOS DULT-derived alert; Tile Scan-and-Secure (iOS app, manual)	Yes — DULT + Tile app	Android DULT alert; Tile Scan-and-Secure (Android app, manual)	Yes — DULT + Tile app
Chipolo ONE Spot / CARD Spot (Find My)	iOS “Found Moving With You” (same as AirTag path)	Yes — automatic	Android DULT alert; AirGuard also covers Find My–format beacons	Yes — DULT
Any NFC-capable tag (AirTag, SmartTag2, some Chipolo/Pebblebee)	NFC tap to open the tag’s contact URI — manual identification, not an alert	Any iPhone with NFC	NFC tap to open the tag’s contact URI — same browser-based path	Any Android with NFC

Notes on detection confidence. Automatic DULT alerts on both OSes require the tracker to have been traveling with the alerting phone for a minimum time and distance — a threshold designed to suppress false alerts from, e.g., sitting next to someone on a bus for a few minutes. The exact thresholds are not published by Apple or Google but are on the order of tens of minutes to a few hours of consistent co-location. Short-duration or intermittent co-location may not trigger the alert even if a tracker is present. The manual detection apps (Tracker Detect, AirGuard, Tile Scan-and-Secure) complement automatic alerts for scenarios where the owner suspects tracking but the automatic threshold hasn’t fired.

9.9 Per-Tracker “Works With” Summary Table

A one-stop reference for the purchase decision. “Works with” means the full owner experience — register + locate + be-found-by — not just detect.

Table 3 — 9. Per-Tracker "Works With" Summary Table

Tracker	iPhone (any)	Android — Galaxy	Android — non-Samsung	Network scale (be-found-by)	UWB precision homing	Cross-ref
Apple AirTag	Yes — full register + locate + be-found-by	No — detect only (DULT + Tracker Detect + NFC)	No — detect only	~1B+ Apple devices — largest in category	Yes (iPhone 11+, U1/U2)	Vol 5, Vol 6
Samsung SmartTag (EI-T5300)	No — no register, no locate, detect only	Yes — full (Galaxy phone + Samsung account)	No — detect only (DULT)	Samsung Galaxy install base — moderate globally; strong in Samsung-dominant regions	No — BLE only	Vol 7 §4.2
Samsung SmartTag+ (EI-T7300)	No	Yes (Galaxy)	No	Samsung Galaxy install base	Yes (Galaxy UWB phones — see Vol 7 §8.2)	Vol 7 §4.3
Samsung SmartTag2 (EI-T5600)	No	Yes (Galaxy)	No	Samsung Galaxy install base	Yes (Galaxy UWB phones)	Vol 7 §4.4
Tile Mate / Pro / Slim / Sticker	Yes — full (Tile app + Tile account)	Yes — full (Tile app + Tile account)	Yes — full (Tile app + Tile account)	Tile app install base + Amazon Sidewalk — smaller than Find My; cross-platform	No	Vol 8 §3
Chipolo ONE Spot / CARD Spot (Find My)	Yes — full (Find My + Apple ID)	No — detect only	No — detect only	~1B+ Apple Find My devices	No	Vol 8 §4.3
Chipolo POINT / CARD POINT (Google FMD)	No — detect only	Yes — full (Google account)	Yes — full (Google account)	Android FMD network (growing; opt-in; see §11)	No	Vol 8 §4.4
Pebblebee Clip/Tag/Card (Find My)	Yes — full (Find My + Apple ID)	No — detect only	No — detect only	~1B+ Apple Find My devices	No	Vol 8 §5
Pebblebee Clip/Tag/Card (Google FMD)	No — detect only	Yes — full (Google account)	Yes — full (Google account)	Android FMD network	No	Vol 8 §5

[FIGURE SLOT — Vol 9, § 9] A smartphone screen (iPhone or Android) showing an OS-native unknown-tracker alert — the “Item Found Moving With You” iOS alert or the equivalent Android DULT alert. Key annotations: (1) the alert notification or modal; (2) the tracker type identified (e.g., “AirTag” or “Unknown accessory”); (3) the action options (Play Sound / Directions / Dismiss / Learn More). This figure anchors the detect verb for the reader and is the primary photo reference for this volume — the moment when cross-platform detection becomes real for the user. Source: Apple press imagery or bench screen capture when hardware is available. For Android, Google’s Find My Device blog (May 2023) published illustrative screenshots of the DULT alert UI. Caption when filled: “Figure 9.1 — An OS-native unknown-tracker alert: iOS (shown) raises this modal when an unrecognized AirTag or DULT-compliant tracker has been traveling with the user. Android raises a structurally similar alert via the DULT implementation. Detect is the one verb both OSes share across all tracker ecosystems. Screenshot courtesy of Apple Inc. (reference).“

9.10 Second-Hand and Cross-Ecosystem Gotchas

The matrix in §3 covers the normal purchase-and-use case. Several edge cases arise in the real world that do not fit neatly into the matrix cells.

Table 4 — 10. Second-Hand and Cross-Ecosystem Gotchas

Scenario	What happens	Resolution / Notes
Bought a used AirTag — previous owner didn’t remove it from their account	The tag shows the Connect sheet when near an iPhone but refuses to complete registration. iOS displays a message that the tag is linked to another Apple ID. The original owner must remove it from Find My (Find My → Items → the tag → Remove Item) before a new owner can pair it.	Contact the original owner if possible. If the original owner’s account is inaccessible, Apple’s support process can remove an orphaned binding under certain conditions — serial number (from NFC tap) and proof of purchase are typically required. No Android path.
Received a SmartTag as a gift; I have an iPhone	The tag is completely non-functional as a tracker. No registration path. The button does nothing without SmartThings.	Exchange the tag for a Tile or a Chipolo ONE Spot (Find My).
Received a SmartTag as a gift; I have a non-Samsung Android (Pixel, etc.)	Same outcome — no registration path for non-Galaxy Android.	Same resolution — Tile or Chipolo POINT are appropriate substitutes.
Switched from iPhone to Android (or vice versa) — have existing AirTags	AirTags bound to an Apple ID remain registered to that Apple ID; the owner’s Android phone cannot access them. The tags continue to be found by the Find My network, but the owner cannot query or use them from the Android phone.	Remove the tags from Find My before switching ecosystems if you intend to use a tracking solution. Re-pair to a Tile account or obtain a new Android-compatible tracker.
Switched from Galaxy to iPhone — have existing SmartTags	SmartTags remain bound to the Samsung account. The iPhone cannot access SmartThings Find.	Samsung account remains accessible on any browser (samsung.com) for account management; the tags cannot be used as trackers from the iPhone.
Bought a Chipolo POINT (Google SKU) intending to use it on an iPhone	No registration path. The tag is permanently a Google FMD–only device; there is no firmware update or re-pairing mechanism to move it to Find My.	Return and exchange for a Chipolo ONE Spot (Find My SKU). The two SKUs look nearly identical on the shelf — verify packaging carefully.
AirTag in Lost Mode — Android phone finds it	The Android phone can NFC-tap the AirTag to open found.apple.com, which displays the owner’s contact info (if Lost Mode is on) and a custom message. The finder can contact the owner via the displayed info. No registration or map access involved.	This path works correctly and is documented in Vol 4 §2.4.
SmartTag2 in Lost Mode — iPhone finds it	iPhone can NFC-tap the SmartTag2 (which added NFC in 2023, unlike the 2021 models). Samsung’s analog of found.apple.com (Samsung’s found-item web experience) opens and shows owner contact info if Samsung’s equivalent of Lost Mode is active.	The original SmartTag (EI-T5300) and SmartTag+ (EI-T7300) have NO NFC — there is nothing to tap.
Android user wants UWB precision homing	No Android-compatible tracker with UWB that an iPhone user cannot also use is available at the consumer level. Samsung SmartTag+/SmartTag2 have UWB on Galaxy UWB phones; no Find My–compatible UWB tracker exists for Android.	Galaxy phone + SmartTag+/SmartTag2 for UWB. Or accept BLE proximity-only finding (Tile, Chipolo POINT). The UWB precision homing gap is a real capability deficit for non-Galaxy Android in the current tracker market.

9.11 Network Density and the Be-Found-By Dimension

The be-found-by column in the matrix is technically a Yes/No, but “Yes — 1 billion Apple devices” and “Yes — Tile app install base” are not the same practical answer. The density of the be-found-by network directly controls how often a lost tag receives a location fix and how fresh that fix is.

   Crowdsourced finder network — approximate scale comparison (2024–2026)
   ═══════════════════════════════════════════════════════════════════════

   Apple Find My
   ██████████████████████████████████████████████████  ~1B+ devices
   All iPhone/iPad/Mac iOS 14.5+ participate (opt-out rare); auto-enrolled

   Google Find My Device (relaunched April 2024)
   ████████████████████████████████████  Android phones w/ Play Services
   Opt-in (most users participate); growing; exact size not disclosed by Google

   Samsung SmartThings Find
   ████████████████████  Galaxy phones w/ SmartThings Find enabled
   Not all Galaxy phones auto-enroll; regional density varies significantly

   Tile Network + Amazon Sidewalk
   ████████████  Tile app install base + Sidewalk hardware
   Requires Tile app on finding phone; Sidewalk (Echo/Ring) adds fixed nodes

   ← Bars are approximate and schematic; exact numbers are not publicly disclosed
     by any network operator. The relative order reflects industry estimates.

Table 5 — 11. Network Density and the Be-Found-By Dimension

Network	Finder device pool	Auto-enrolled?	Key strength	Key weakness
Apple Find My	~1B+ Apple devices (iPhone, iPad, Mac)	Yes — all iOS 14.5+, opt-out only	Largest by far; extremely dense in NA/EU/Japan/Australia	Lower density in Android-dominant markets; network capped to Apple-device geography
Google FMD (April 2024+)	Android phones with Google Play Services	Opt-in (most users participate)	~3B+ Android devices theoretically reachable if all opt in; growing rapidly	Opt-in vs auto-enrolled means effective size < theoretical size; newer network with less historical density
Samsung SmartThings Find	Samsung Galaxy phones	Opt-in within SmartThings app	Very dense in South Korea; meaningful share in Samsung-dominant Asian markets	Small share in North America/Western Europe where Galaxy is minority; not all Galaxy phones enroll
Tile + Sidewalk	Phones with Tile app + Amazon Sidewalk hardware	App-install opt-in	Cross-platform (iPhone + Android finders); Sidewalk adds stationary coverage	Smallest phone-based pool; dependent on app adoption; Sidewalk coverage limited to Sidewalk-hardware geography (mostly US)

The regional flip. The network density picture inverts by geography:

North America, Western Europe, Australia, Japan: Apple Find My wins decisively — iPhone market share is 40–60% in these markets, and auto-enrollment means nearly every iPhone participates. Google FMD has a large but smaller enrolled pool; SmartThings Find has a meaningful but smaller Galaxy install base.
South Korea, India, Southeast Asia: Samsung has dominant Galaxy share in South Korea; SmartThings Find density there is high. India and many Southeast Asian markets are Android-dominant, which favors Google FMD (growing) over Apple Find My.
Global edge cases: In very low-density rural areas or developing markets with lower smartphone penetration overall, all crowdsourced networks underperform relative to their advertised scale. A lost tag in a sparsely populated area may receive infrequent finds from any network.

The practical takeaway for the purchase decision: the be-found-by network is not a spec line — it is a lived experience that depends on where you live and travel. A North American or European user who loses a SmartTag in their own city will receive fewer location reports per hour than if they had lost an AirTag — not because the SmartTag is worse hardware, but because the pool of nearby Galaxy phones is smaller than the pool of nearby iPhones. A buyer in Seoul has a different calculation.

9.12 Cheatsheet Updates

The following bullets feed Vol 15 (the printable cheatsheet):

The four verbs — definitions for the laminate card:

Register = pair + bind to cloud account + become owner of record. Requires compatible phone OS and cloud account. Most locked-down verb.
Locate = see on a map, play speaker, precision-home to it. Requires being the registered owner.
Be-found-by = a stranger’s phone silently reports the tag’s location. Depends on the finding network, not the owner’s phone.
Detect = OS or app alerts you that an unknown tag is traveling with you. Cross-platform via DULT; the one verb both OSes share across all networks.

Key asymmetries — cheatsheet bullets:

AirTag: iPhone → register + locate + be-found-by (best network) + detect. Android → detect only + NFC-read. Android can never own or map-locate an AirTag.
SmartTag: Galaxy phone → full. iPhone → detect only (DULT). Non-Samsung Android → detect only (DULT). Galaxy-only is the hardest ecosystem wall in the category after Apple.
Google FMD tags (Chipolo POINT, Pebblebee Google): Android → full. iPhone → detect only.
Tile: iPhone or Android → full (Tile app). The only register-on-either-OS network.
Chipolo / Pebblebee: one network per SKU, chosen at purchase, irreversible. Find My SKU → iPhone only (for ownership). Google SKU → Android only (for ownership). Detect works cross-platform via DULT on either.
DULT = the Apple+Google cross-platform detect cooperation. Both OSes can now alert on the other ecosystem’s trackers. Detect is cross-platform; ownership is not.

Android + AirTag quick-ref:

Register? No. Locate? No. Be-found-by? Via iPhones near the tag — Android doesn’t contribute. Detect? Yes (DULT + Tracker Detect + AirGuard). NFC-read? Yes (any NFC Android).

SmartTag catch for the field card:

SmartTag registration requires Samsung Galaxy phone + Samsung account. iPhone users get nothing. Non-Galaxy Android users get nothing. Check before buying.

Network density quick-ref:

Find My: ~1B+ devices, auto-enrolled, iPhone geography → highest density in NA/EU/Japan/AU.
Google FMD: Android opt-in, growing post-April 2024 → strong in Android-dominant markets.
SmartThings Find: Galaxy phones only → strong in South Korea; moderate elsewhere.
Tile: app-install only → smallest phone-based pool; Sidewalk adds US fixed coverage.

AirTags Volume 9 — Which Works on Which Phone: The Network Map