Last updated: September 21, 2026
Aster ("the app") is a habit-tracking app that works offline, with an optional weekly report correlating your habits against health data you choose to connect. This policy explains what data the app handles.
Benjamin Masoldt
Am Eichenhain 36
91598 Colmberg
Germany
Email: benjamin@masoldt.de
Aster does not require an account and does not collect, store, or transmit any personal information to us. There are no servers operated by us — the app has no backend.
Data stored on your device only:
Your habits, their completion history, reminder times, and the colors you pick in the monthly view are stored locally on your device using a standard on-device database. None of this leaves your device, and it's deleted if you uninstall the app. You can export a copy of it at any time from within the app (Settings → Export your data) — that export is created and shared entirely on your device, through whichever app you choose to send it to; we never see it.
Health data (optional):
If you choose to connect Apple Health or Google Health Connect, the app reads step count, sleep, and heart rate variability (HRV) data — only with your explicit permission, granted through your device's own health-permission screen, which you can revoke at any time in your device settings. This data is read-only (the app never writes to Apple Health or Health Connect), is processed entirely on your device to generate your weekly insight report, and is never transmitted anywhere — not to us, not to any third party. Health data is treated by GDPR as a special category of personal data, which is why connecting it is entirely optional and off by default; the app's core habit-tracking features work fully without it.
Notifications:
Reminder notifications are scheduled locally on your device. No push-notification service or third-party server is involved.
Purchases:
Subscription and lifetime purchases are processed by Google Play Billing and RevenueCat, our purchase management provider. To process your purchase and verify your entitlement, RevenueCat receives a randomly generated anonymous user ID and standard purchase/transaction data from Google Play (such as product ID, purchase token, and transaction date). This is not linked to your name, email, or any other personal identifier by us. See RevenueCat's own privacy policy for how they handle this data: revenuecat.com/privacy.
Aster does not collect your name, email address, location, contacts, photos, or any other personal information. Nothing is collected offline or online except for the purchase/restore flow, and the optional health data described above, which never leaves your device.
If you are located in the EU/EEA, you have rights under the General Data Protection Regulation, including the right to access, rectify, restrict, or object to processing of your personal data, the right to data portability, and the right to erasure ("right to be forgotten," Art. 17 GDPR).
In practice, Aster holds almost no personal data itself — your habits, history, and any connected health data live only on your device, and we cannot access or delete those remotely (uninstalling the app removes them). The only data connected to you indirectly is the anonymous purchase record held by RevenueCat/Google Play for your subscription or lifetime purchase. To request erasure or have questions about this data, contact us at the email below; we will forward the request to RevenueCat where legally possible. Note that revenue-relevant transaction records may need to be retained under German tax law (§147 AO), even after an erasure request.
You also have the right to lodge a complaint with a data protection supervisory authority.
Aster is not directed at children and does not knowingly collect data from children.
If Aster's data practices change (for example, if crash reporting or analytics are added in a future update, or if health data starts being used to auto-complete habits directly), this policy will be updated accordingly before that update is released.
Questions about this policy can be sent to: benjamin@masoldt.de