Station Master is a metro transit companion app that helps you scan and save metro cards, view balances and trip history, see timetables and fares, and navigate stations using maps and a compass-style wayfinder.
We are committed to respecting your privacy. This policy explains what data the app uses, how it is stored, and your options.
All data described in this section is stored locally on your device only. The app does not send this data to our own servers.
When you scan a compatible metro card using NFC, the app may read and store:
Purpose: Show card balance and recent trip history inside the app, and let you quickly reopen a saved card without rescanning.
Storage: Saved in a local SQLite database inside the app sandbox. Data remains on your device until you delete the card or uninstall the app.
The app stores simple preferences such as selected language and theme (light/dark/system).
Purpose: Remember your UI preferences between sessions.
Storage: Stored locally using MMKV in the app sandbox.
The app may request access to your device location when you use map-related features.
What we use: Approximate or precise location (depending on system permission) while the map is active.
Purpose: Show your position on the metro map and help you find nearby stations and card booths.
Sharing with third parties: Map tiles are loaded from third-party providers (for example, OpenFreeMap, Mapbox). When tiles are requested, those providers can see your IP address and other standard HTTP request information, which may reveal rough location. We do not send your location to our own servers.
The app uses your device’s NFC capability to read compatible metro cards.
What we read: Card identifier, balance, and history data exposed by the card.
Purpose: Show your card balance and history in the app, and optionally save card information to your device for later reference.
The app uses the device magnetometer (compass sensor) to provide a simple wayfinding experience in some screens. The accelerometer is used to determine if the device is lying flat, primarily for UI adjustments.
Purpose: Show an approximate direction to a selected station or location. Sensor readings are processed locally and are not transmitted to our servers.
We use the data described above only to provide the core features of the app:
We do not:
Station Master is not specifically targeted at children. If you believe a child has used the app and you have questions about data, please contact us using the information below.
The app may interact with third-party services such as:
When you open an external app or link, that third party’s own privacy policy applies.
If you have privacy questions, requests, or concerns about Station Master, please reach out:
Developer: princebillygk@gmail.com
Last updated: January 23, 2026