Tankbook — Privacy Policy
Last updated: October 1, 2026
This policy explains what data Tankbook ("the app") handles. The app is published by The Alchemist Code ("we").
The short version
- There is no account. We never ask for your name, email or password.
- Your vehicles, fill-ups, odometer readings, fuel prices, gas stations you type, expenses, maintenance reminders and settings are stored only on your device. We do not upload them anywhere.
- Reminders are scheduled on your phone. No server sends them.
- The app does not use your location, camera or photos.
- The app shows ads and uses analytics and crash reporting. Those services, run by Google, collect some technical data, described below.
Data stored on your device
Your vehicles (names, type, make, model, year, fuel type, tank size and odometer), fill-ups (date, odometer, amount of fuel, price, total, fuel type, the gas station name you type and notes), expenses, maintenance reminders and settings. They stay on your phone.
- Backup file and CSV export: the app creates these files only when you ask. You decide where to save them and who to share them with. We never receive them.
- Android backup: if backup to your Google account is turned on in your phone's settings, Android may include the app's data in your device backup so it comes back when you move to a new phone. Android makes that backup and stores it encrypted in your Google account. We have no access to it.
You can erase everything at any time in Settings › Delete all my data. Uninstalling the app also removes it from the phone.
Data collected by third-party services
| Service | What it collects | Why |
|---|---|---|
| Google AdMob (ads) | IP address (used to estimate approximate location), Android advertising ID and app set ID, interactions with ads and the app, performance diagnostics | Showing ads, measuring them, preventing fraud |
| Google Analytics for Firebase | App-instance ID, advertising ID, approximate location derived from a masked IP address, screen views, sessions and purchase events | Understanding how the app is used |
| Firebase Crashlytics | Crash stack traces, device metadata at the time of a crash, app state, an installation identifier | Finding and fixing crashes |
| Firebase Remote Config | Country, language, time zone, OS and app version | Adjusting app settings remotely |
| Google Play Billing | Payment details and your purchase | Processing your one-time Premium purchase (we never see your card) |
All of this data is encrypted in transit. Each provider handles it under its own privacy policy:
- Google: https://policies.google.com/privacy
- How Google uses data from apps that use its services: https://policies.google.com/technologies/partner-sites
Your choices
- Ad personalization (EEA, UK, Switzerland): the app asks for your consent before showing personalized ads, and you can change your choice anytime in Settings › Ad privacy options.
- Advertising ID: you can reset or delete it in your Android settings under Privacy › Ads.
- Notifications: maintenance reminders are optional. You can deny the permission and still see them inside the app, or revoke it anytime in Android settings.
- Premium removes all ads.
Children
The app is not directed at children under 13 and we do not knowingly collect data from them.
Changes
If this policy changes, the new version will be posted at this address with an updated date.
Contact
contact@thealchemistcode.org