Your smart ring data inside Apple Health: how the bridge works

I found this personally annoying: Galaxy Watch on the wrist, iPhone in the pocket, and the Health app only showing iPhone data. The ring I wear at night records detailed sleep stages, but Apple Health doesn't see them. FitMesh's Apple Health write bridge was born from this concrete need, not from a feature checklist.

The problem: two ecosystems that don't talk to each other

Android and iOS use separate, non-interoperable health data repositories: Health Connect on Android, HealthKit on iOS. A Galaxy Watch paired with an Android phone writes data to Health Connect, not Apple Health. A Colmi ring read via Bluetooth by FitMesh on Android does the same. Result: if you open the Health app on your iPhone, that data isn't there.

How the bridge works: step by step

1. Collection on Android: FitMesh Sync reads data from your Android wearable (via Health Connect for Galaxy Watch, via Bluetooth for the Colmi ring) and uploads it to EU cloud.
2. FitMesh EU cloud: data is archived with timestamp, source, data type and user account. The cloud normalizes formats across different sources.
3. iOS app active: when you open FitMesh on iPhone (or the app is active in background), it checks what data is available in the cloud for your account.
4. Duplicate check: for each available piece of data, the app checks whether Apple Health already has something for that time slot. If yes, it skips. If no, it writes.
5. Targeted writing: writes to Apple Health only the missing data. If Apple Watch has already recorded sleep from 11pm to 7am, FitMesh doesn't touch those hours.
6. Immediate visibility: after writing, data appears in the iPhone Health app like any other HealthKit entry — with the source clearly shown as FitMesh Sync.

No duplicates: how it works

Before writing any data, FitMesh checks whether Apple Health already has something for that time slot. If yes, it moves on. If no, it writes. In practice: there are never two entries for the same hour.

Sleep with stages: the ring's strong point

Smart rings like the Colmi R02/R03 are built for nighttime: they measure sleep, SpO₂, heart rate and variability while you sleep, without the bulk of a watch on your wrist. The stages recorded by the ring (deep, light, REM, awake) show up in Apple Health in the Sleep chart — just as if Apple Watch had recorded them.

Privacy: where data goes and who sees it

Data takes just two steps: from the FitMesh app on Android to the FitMesh cloud (EU datacenter, encrypted), then from the FitMesh app on iPhone into Apple Health on your device. FitMesh doesn't sell data to third parties, doesn't use it to train models, doesn't share it with advertisers. The EU cloud guarantees GDPR compliance.

How to activate the bridge

1. Install FitMesh Sync on iPhone (TestFlight beta now, App Store coming soon).
2. Sign in with the same account you use on Android.
3. Go to Settings → Apple Health → Write Bridge.
4. Toggle it on and grant the requested HealthKit permissions.
5. Choose which data types you want the bridge to write (sleep, steps, heart rate, etc.).
6. FitMesh syncs available data and writes it to Apple Health within minutes.

In summary

• •The Apple Health write bridge brings Android device data (smartwatches, smart rings) into HealthKit on iPhone via FitMesh EU cloud.
• •Checks first whether Apple Health already has that data. Writes only where something is missing. No duplicates.
• •Sleep with full stages (deep, light, REM): ring stages appear in Apple Health in the same format as Apple Watch.
• •Opt-in, granular, revocable: activated from FitMesh iOS settings and turned off at any time. HealthKit permissions are managed from iPhone Settings.
• •EU/GDPR privacy: EU datacenter cloud, encrypted, no data sales or third-party sharing.