HeartStress is a local-first cardiac trend app. We believe heart and sleep data is among the most sensitive personal health information. This policy explains exactly how we handle your data.
1. Data we read
Only with your permission, we read the following health metrics through Apple HealthKit: heart rate, heart rate variability (HRV), resting heart rate, sleep stages, activity and workout records, respiratory rate.
We do not collect device identifiers, IP addresses, behavior events or advertising identifiers. There is no account system, and no personal information is requested.
2. Where data is stored
All derived data (HSI scores, trend caches, symptom logs) is stored locally in your device's SwiftData database, encrypted by the iOS sandbox.
If you enable iCloud Backup for HeartStress, the backup itself is end-to-end encrypted by Apple. We have no access to it.
3. Data transmission
We do not operate any backend server. The app does not upload your heart, HRV, sleep, or any derived data anywhere.
We do not integrate third-party analytics SDKs (Google Analytics, Firebase, Sentry, Mixpanel, etc.) or advertising SDKs.
4. In-app purchases & subscriptions
Pro subscriptions are processed by Apple StoreKit. Payment records live with Apple. The only thing we see is whether the current Apple ID has a valid Pro entitlement — and even that check is performed locally.
To cancel, go to Settings → Apple ID → Subscriptions. Refunds are handled by Apple.
5. Your control
Revoke HealthKit access: HeartStress only reads what you grant via HealthKit. Go to iOS Settings → Privacy → Health → HeartStress and turn off the relevant toggles — the app will immediately stop reading new data.
Uninstalling clears local state: derived scores live in the app's iOS sandbox, encrypted by the system. Removing HeartStress deletes that local state. Your original HealthKit data is managed by iOS itself and is not affected by uninstalling the app.
6. Policy changes
If we make a material change to this policy, we will notify you prominently in-app and update the effective date. Continued use constitutes acceptance.
7. Contact
Questions about this policy? Email: oneplayer_app@outlook.com