Privacy Policy
Japan Train Card Balance Check
Your card is read on your device, and your balance and trips are stored only on your phone — that data is never uploaded. There is no account. The app is free and ad-supported, and it reports anonymous usage and crash information to Google Firebase so we can see what breaks and what gets used.
- No personal data required to use the app
- No account needed
- Contains ads
- Limited sharing with named partners
This Privacy Policy explains how MobileMint (“we”, “us”) handles information in connection with the Japan Train Card Balance Check mobile application (the “App”). It applies to the App only. By using the App, you agree to the practices described here.
Information we collect
We are deliberately minimal about data. The App collects only what is described below, and nothing more:
| Data | Why & how |
|---|---|
| NFC card reading | Used only to read your transit card's balance and stored journeys when you hold it to your phone. The app can read the card but never modify it, and it cannot add balance. |
| Card data (on device) | Balances, journeys, and any nickname you give a card are saved locally on your phone so your history outlives the card's own 20-journey limit. They are never uploaded, and you can erase them at any time in Settings. |
| Advertising identifier | Your device's advertising ID and coarse device information are used by Google AdMob to show ads and to limit how often you see the same one. This is handled by Google, not by us — we never receive it. |
| Usage events | Anonymous counts of what happens in the app — that a scan succeeded and how many journeys it found, that a scan failed and why, that a card was renamed, that the language was changed. Never your balance, your stations, your card number or a nickname: no card data is included in any event. |
| Crash and performance diagnostics | If the app crashes or runs slowly, the device model, OS version, app version and a stack trace are sent so the fault can be found and fixed. |
| Push notification token | A device token from Firebase Cloud Messaging, used only to deliver app notices. You are asked for permission first, and the app works normally if you decline. |
How we use information
We use the information above solely to operate, maintain, and improve the App — for example, to provide its core features, keep it stable by diagnosing crashes, and understand which features are useful in aggregate. We do not use your information for profiling unrelated to the App, and we never sell it.
Analytics
The App uses privacy-conscious analytics to collect aggregated, anonymous information about usage and stability. This helps us fix bugs and decide what to build next. These analytics are not used to identify you personally.
Advertising
The App is free and supported by advertising. Our advertising partner may use your device’s advertising identifier to show ads and limit how often you see the same ad. You can reset or limit this identifier at any time in your device settings under Settings → Privacy → Ads. We do not share your name, email, or contacts with advertisers.
Third-party services
We rely on a small number of trusted service providers. Each processes data only as needed for the purpose listed and under their own privacy policy:
- Google AdMob— Shows the ads that keep the app free, and applies frequency limits so the same ad is not repeated..Privacy policy ↗
- Google Firebase (Analytics, Crashlytics, Performance Monitoring, Cloud Messaging)— Anonymous usage counts, crash reports, performance measurements, and delivery of push notifications. No card data is ever sent..Privacy policy ↗
Data storage & security
Your in-app content is stored locally on your device by default. No method of transmission or storage is ever 100% secure, but we take reasonable measures to protect your information against unauthorised access, alteration, or loss.
Children’s privacy
The App is not directed to children under 13, and we do not knowingly collect personal information from children. If you believe a child has provided us information, contact us and we will delete it.
Your rights & choices
Depending on where you live (including under the GDPR and CCPA), you may have the right to access, correct, export, or delete your personal information, and to object to or restrict certain processing. Because the App stores your content on your device, you can remove it at any time by clearing the App's data or uninstalling it. To exercise any right, email us at the address below and we will respond within 30 days.
Data deletion
Your card data lives on your phone alone, so erasing it is immediate and needs no request to us. Anonymous usage and crash reports held by Firebase are not tied to your identity; uninstalling stops any further reporting, and you can ask us to purge what has already been collected.
- 1Open the app and go to the Settings tab.
- 2Under Data, tap "Delete local data".
- 3Confirm. Every saved card, its nickname, and its stored journey history are removed from the phone straight away.
- 4To remove everything at once instead, uninstall the app — all of its local data goes with it.
Data retention
We keep personal information only as long as needed to provide the App and for legitimate legal or operational reasons. Anonymous, aggregated analytics may be retained to understand long-term trends. When you delete your data, we remove it from active systems promptly and from backups within a reasonable period.
Changes to this policy
We may update this policy as the App evolves. When we make material changes, we will update the date below and, where appropriate, notify you in the App. Continued use after an update means you accept the revised policy.
Contact us
Questions about this policy or your data? Email us at rasel.dev.cse@gmail.com. We read every message.
Last updated August 29, 2026 · MobileMint · Japan Train Card Balance Check 0.1.2