Last updated: July 17, 2026
Fastwell ("we", "us", the "App") is an intermittent‑fasting timer developed by Vadim Semenko. This Privacy Policy explains what data the App processes, how it is used, where it is stored, whether it is shared, and how long it is kept. Fastwell is built to be private by design: there is no account, and your fasting and weight data stay on your device.
When you start a fast, log your weight, or change a plan, the App records this locally using Apple's on‑device database (SwiftData). Your fasting history, fasting stages, streaks, notes and weight entries are stored inside the App's private sandbox on your device. This data is not sent to us or to any third party.
If you enable the Apple Health integration, the App reads and writes your body‑weight entries through Apple's HealthKit so your weight stays in sync with the Health app. HealthKit data is stored and managed by iOS on your device; Fastwell does not upload your Health data to our servers, and we never use Health data for advertising or share it with third parties. You can turn this off at any time in iOS Settings → Health or in the App's Settings.
If you enable reminders (fast complete, halfway, or eating‑window alerts), the App schedules local notifications on your device. These are generated and delivered locally by iOS; we do not operate a push server and do not receive your notification content.
To understand which features are used and to fix crashes, the App uses Google Firebase (Firebase Analytics and Crashlytics). This processes:
This data is not linked to your real‑world identity and is not used to track you across other companies' apps or websites, and is not used for advertising. See Google's privacy information at firebase.google.com/support/privacy.
Fastwell offers optional auto‑renewing subscriptions (Fastwell Premium). Purchases are processed by Apple through your Apple Account; we never see your payment card or full Apple Account details. To manage subscriptions and validate entitlements we use RevenueCat, a subscription infrastructure provider. RevenueCat processes a randomly generated app user ID, a device identifier, and your purchase history (which product you bought and its status) solely to deliver and restore your subscription. This data is not used to track you across other apps or websites and is not linked to your real‑world identity. See RevenueCat's privacy policy at revenuecat.com/privacy.
We do not collect your name, email, contacts, precise location, or browsing activity, and we do not use your data for tracking or advertising.
Your fasts, weight and history remain on your device until you delete them. Aggregate analytics and diagnostic data are retained by Google/Firebase according to their standard retention settings. Subscription records held by Apple and RevenueCat are retained as needed to provide and account for the subscription service.
You can erase all locally stored content at any time via Settings → Privacy → Delete all data inside the App, which permanently removes every fast, weight entry, note and setting on your device. Deleting the App also removes all locally stored content.
The App is not directed to children under 13 (or the equivalent minimum age in your jurisdiction) and we do not knowingly collect personal data from them.
Fastwell is a wellness and educational tool. It is not a medical device and does not provide medical advice, diagnosis or treatment. Fasting is not appropriate for everyone. Consult a qualified healthcare professional before starting any fasting routine, especially if you are pregnant, breastfeeding, under 18, or have a medical condition such as diabetes or an eating disorder.
We may update this Privacy Policy from time to time. Material changes will be reflected by updating the "Last updated" date above.
Questions about this policy or your data? Email [email protected].
© 2026 Vadim Semenko. All rights reserved.