한국어
ShiftRhythm (the "app") provides body-clock (circadian rhythm) guidance for shift workers. The app does not collect or transmit any personal information; all computation happens on your device. This policy explains what that means.
1. Information we do not collect
- Personally identifying information such as name, email, or phone number
- User accounts (the app has no login or sign-up system)
- Sensitive permissions such as location, contacts, photos, or microphone
- Advertising identifiers or tracking data (the app contains no ad or analytics SDKs)
2. Information processed only on your device
The app stores the following only on your device (iOS SwiftData and App Group storage) and never transmits it:
- Shift patterns, shift start/end times, and per-day corrections you enter
- Custom patterns you build
- App settings (such as whether Apple Health integration is on)
- Body-clock estimate caches (phase computation results)
3. Apple Health (HealthKit) data
If you turn on Apple Health integration, the app uses the following data read-only to improve its estimates:
| Data | Purpose |
|---|
| Sleep stages | Sleep score · circadian alignment estimate |
| Step count (activity) | Light exposure estimate |
| Heart rate variability (HRV) | Recovery signal estimate |
| Resting heart rate | Recovery signal estimate |
| Wrist temperature | Condition reference |
- This data never leaves your device. It is not sent to any server or shared with third parties.
- The app does not write to Apple Health (read-only).
- Integration is optional; if you decline or turn it off, the app works from your schedule alone.
- You can change permissions anytime in the iOS Health app → Data Access & Devices.
4. Network use
- The app does not communicate with any developer server or external service (no account, no server).
- Data sync between iPhone and Apple Watch uses Apple's WatchConnectivity, directly between your own two devices, without passing through anything external.
5. Third-party SDKs and advertising
The app contains no advertising, analytics, or tracking SDKs. No data is sent to third parties.
6. Data retention and deletion
- All data is stored only on your device (deleted together when you delete the app).
- To delete in-app: App → Settings → "Delete All Data".
- The app keeps no copy of Apple Health data, so turning the integration off stops all reading.
7. Children
The app is rated 4+. We do not knowingly collect information from children under 13.
8. Medical disclaimer
The app provides reference information to help you manage your daily rhythm. It is not a medical device or diagnostic tool, and is not intended to diagnose, treat, or prevent any disease. Consult a professional for health concerns.
9. Changes
If this policy changes, the "Last updated" date on this page will be updated when the app version applying the change is released.
10. Contact