Privacy Policy ยท Effective August 13, 2026
Fenster is a fasting clock. It is built so that your data stays with you.
Nothing. Fenster has no accounts, no analytics, no tracking, and no servers. We cannot see your fasts, your weight, your health data, or anything else, because none of it is ever transmitted to us or to anyone.
Deleting the app deletes this data.
If you connect Apple Health, Fenster reads your date of birth, height, and weight to fill your profile and to show safety-relevant cautions. Reading happens on your device; the values are displayed, not uploaded.
Fenster writes exactly one thing to Apple Health: a body-weight entry, and only when you tap "Save to Health." Every entry is marked as user-entered. Fasting windows are never written to Apple Health.
You can revoke Health access at any time in the Health app under Sharing.
The optional lifetime unlock is processed entirely by Apple through the App Store. We receive no payment details and hold no purchase records; your entitlement is tied to your Apple ID and restored by Apple.
All notifications are scheduled locally on your device. There are no push servers.
Fenster is not intended for anyone under 18. The app states this and asks; if Apple Health indicates an age under 18, the app repeats the safety notice.
If this policy ever changes, the new version will be published at this address with a new effective date. Since Fenster collects nothing, there is little to change.