Zone
Privacy Policy
Last updated 25 August 2026 · Applies to the Zone mobile app on iOS and Android
Zone has no backend. There is no account to create, no server to sync to, and no analytics or advertising SDK in the app. Everything you log is written to storage on your own phone and stays there. This is how the app is built, not a promise about how we behave.
Who this is from
Zone is made by Barış Yırtıncı, trading as yirtinci, an independent one-person developer. Questions about this policy, or about data held on your device, go to [email protected].
What Zone stores, and where
Everything below lives in the app's own storage area on your device. It is removed when you delete the app, and you can erase it from inside the app at any time.
| What | Why it exists | Where it goes |
|---|---|---|
| Sleep logs — bed and wake times, how long you took to fall asleep, time awake in the night, a quality rating, and any factors you tag | The model has nothing to forecast from without them | Your device only |
| Your profile — sleep need, habitual bed and wake times, chronotype answers, caffeine sensitivity | Sets the phase and shape of your curve | Your device only |
| Caffeine doses you log | Drives the decay curve and the cut-off time | Your device only |
| Preferences — language, clock format, theme, reminder settings | So the app behaves the way you set it | Your device only |
What Zone does not do
- No account, no sign-in, no email address collected.
- No analytics, telemetry, crash reporting SDK, or attribution SDK.
- No advertising, and no advertising identifier is read.
- No tracking across apps or websites. The iOS privacy manifest declares
NSPrivacyTracking: falsewith no tracking domains. - No location, contacts, photos, microphone, or health-store access is requested.
- Your sleep data is never sold, shared, or transmitted anywhere.
The one exception: subscriptions
If you buy Zone Pro, the purchase itself is handled by Apple or Google, not by us. We never see your card details, and we do not receive your name or email address.
To know whether your subscription is currently active, the app uses RevenueCat, a subscription-management service. When the app first runs the purchase flow, RevenueCat generates an anonymous identifier for the install — the app does not supply one, and does not attach any personal detail to it. What RevenueCat receives is that anonymous identifier and the store receipt needed to verify entitlement. No sleep data, log, profile field, or preference is ever sent to it.
If you never open the paywall, this exchange does not happen at all. RevenueCat's own policy is at revenuecat.com/privacy.
Notifications
Reminders are scheduled locally on your device by the operating system. Nothing is pushed from a server, because there is no server. If you decline the notification permission the rest of the app works unchanged.
Backups you make yourself
The app can export your history to a JSON file. That file is produced by you, handed to your own share sheet, and goes wherever you send it. Once it leaves the app it is outside our control — if you place it in a cloud drive, that provider's terms apply to it. Zone neither uploads it nor keeps a copy.
Children
Zone is not directed at children under 13, and because there is no account and no collection of personal data, none is knowingly gathered from anyone.
Your rights
Rights such as access, correction, portability and erasure under the GDPR, the UK GDPR, the CCPA and Turkey's KVKK all attach to data a company holds about you. We hold none. In practice:
- Access and portability — Settings → Back up my data exports everything, in a readable JSON file.
- Erasure — Settings → Erase all data removes it, permanently, from the device. Deleting the app does the same.
- Correction — every logged night can be edited or deleted individually.
For the anonymous subscription identifier described above, write to [email protected] with your store receipt and we will ask RevenueCat to delete the associated record.
Changes to this policy
If the app ever starts doing something this page does not describe, this page changes first, and the date at the top changes with it. Material changes will also be surfaced in the app.
Not medical advice
Zone is a wellness tool, not a medical device. It does not diagnose or treat any condition. If you have persistent sleep problems — or suspect a sleep disorder such as apnoea or insomnia — please talk to a doctor.