Tyvin Privacy Policy
Last updated: 2 October 2026
Summary: Tyvin does not collect, transmit or share your personal data. Everything stays on your device.
Who is responsible
Tyvin is developed by Antti Simonen, Finland. Contact: support@tyvin.app.
Data stored in the app
Tyvin stores your fasting history, settings and, if you choose to log it, your body weight. This data is stored only on your device. Tyvin has no server and no user accounts, and the developer cannot access your data.
Tyvin itself does not send your data to any server, including iCloud, and the developer cannot access it. Your device's own features, which are managed by Apple and not by Tyvin, may still copy this data: if you have iCloud Backup enabled, Tyvin's data is included in your device backup, and if you have Health syncing through iCloud enabled, Apple may sync Health data, including weights written by Tyvin, between your devices. These features are governed by your Apple settings and Apple's privacy policy.
Apple Health
If you turn on weight sync with Apple Health, Tyvin reads your body-weight readings from Health and writes the weights you log in Tyvin to Health. This happens only on your device. Tyvin has no server and never sends Health data anywhere, uses it for no other purpose, and does not share it with anyone. Tyvin reads and writes weight only. When you turn sync off, readings imported from Health are removed from Tyvin; readings Tyvin wrote remain in Health until you delete them there. Health data is never used for advertising or marketing. You can manage Tyvin's access in the Health settings of your iPhone.
Notifications
If you allow notifications, Tyvin schedules fasting reminders locally on your device. The notifications are created and delivered by your device itself, not by a server. No notification content or notification-related data is sent to the developer or to any third party. You can turn notifications off at any time in your iPhone's Settings.
Analytics, advertising and third parties
Tyvin contains no analytics, advertising or tracking, and no third-party SDKs that collect data. The one-time purchase is processed entirely by Apple through the App Store; the developer receives no payment details or personal information from you.
Your rights
Because the developer holds no personal data about you, there is nothing to access, correct or erase on our side. You control your data in the app and in Apple Health. Deleting the app removes the data Tyvin stores on your device. You have the right to lodge a complaint with a supervisory authority, in Finland the Office of the Data Protection Ombudsman (tietosuoja.fi).
Children
Tyvin is not directed at children under 13 and does not knowingly collect data from anyone.
Changes
If this policy changes, the updated version will be published at this address with a new date.