Your body data stays yours.

Every fast you start, every stage you cross, every note you write, and every completion is stored locally on your iPhone using Apple’s SwiftData framework. This data is never uploaded to a Fast36 server because we don’t operate one for user data. There is no account, no login, no sync.

If you delete the Fast36 app, the local database is removed with it. If you wipe or reset your iPhone, your Fast36 data goes with it.

• Your name, email address, phone number, or postal address.
• Your location, IP address, or device identifiers (beyond what Apple and RevenueCat require for subscription management — see below).
• Analytics, usage telemetry, screen recordings, or behavioural tracking.
• Crash reports or diagnostic logs, unless you explicitly opt in by sharing them with Apple.
• Advertising identifiers. Fast36 shows no ads and has no ad SDK.

If you grant permission, Fast36 writes completed fasts into Apple Health as workout sessions so they show up alongside your other activity. Fast36 does not read other HealthKit data. HealthKit data is managed by Apple and stored on your device in an encrypted container — Fast36 does not upload or share it.

You can revoke HealthKit access at any time from iOS Settings → Privacy & Security → Health → Fast36.

Fast36 Pro is offered as an auto-renewing subscription (monthly or annual). Payments are processed by Apple through the App Store — we never see your credit card, billing address, or Apple ID. Apple returns an anonymous receipt that tells us whether your subscription is active.

To manage the entitlement (so that Pro features unlock on every device you sign in with), Fast36 uses RevenueCat. RevenueCat receives the App Store receipt and an anonymous identifier that they generate. They do not receive your name, email, HealthKit data, fasting history, or any other personal information. Their privacy policy and data practices are linked above.

Fast36 schedules local notifications on your device to mark stage transitions and fast completion. These never travel to a server. You can disable notifications at any time from iOS Settings → Notifications → Fast36.

Fast36 exposes App Intents so you can start or end a fast with Siri or a Shortcut, and show progress in Home Screen and StandBy widgets. These features run on your device and do not transmit data off it.

If you email the address listed on this site, your message lives in our inbox until we reply. We don’t add you to any marketing system without explicit consent, and we don’t share your email with third parties.

Fast36 is not directed at children under 17. Extended fasting is not appropriate for minors; the App Store age rating reflects this.

If this policy changes materially, the “Last updated” date at the top of the page will move and the change will be noted in the app’s release notes.

Questions about privacy? Email hello@fast36.app.