Android app

Privacy Policy — Math Drill

Last updated: September 27, 2026

This privacy policy applies to the Math Drill Android app (com.gookkis.mathdrill), developed and published by Heri Kiswanto ("we"). It explains what data is processed when you use the app, by whom, and what choices you have.

Quick summary

  • The app does not collect any personal data on our servers. We do not operate a server.
  • There is no account, sign-in, cloud sync, leaderboard, or purchase of any kind.
  • Practice questions are generated on your device, and your answers, scores, streak and session history are stored on that device only.
  • The daily practice reminder is optional and scheduled by the device itself; no notification is sent from a server.
  • The app shows ads through Google AdMob, which as a third party may collect certain data (see below).
  • Beyond that, there is no analytics SDK, crash reporter, tracker, or other third-party service in the app.

Data we collect

None. We do not request, collect, store, transmit, or sell your personal data — including your name, email address, phone number, contacts, photos, location, or the list of apps installed on your device. The app has no backend, no database, and no usage reporting to us.

Your practice results are not an exception to that. Questions are generated by the app on the device, your answers are checked on the device, and the scores are stored on the device. No path inside the app sends an answer, a score, or your session history to us or to anyone else.

The only network traffic the app makes is for loading ads, described below. Drills, results, the mistakes review and your progress all work without a connection.

Data stored on your device

To do its job, the app stores a small amount of data locally in your device's internal storage:

  • your session history: when each session finished, the drill you picked (Basic, General, Test), how many answers were correct out of how many, the average time per answer, the level at the start and end of the session, and the result per operation — your streak, statistics and adaptive level are calculated from this;
  • the details of your last session — each question, the answer you typed and the correct one — so that its mistakes can be reviewed; only the last session is kept for this;
  • the level last reached in each drill, and the drill you picked most recently;
  • your daily reminder setting: on or off, and the time you chose;
  • your display preference: light theme, dark theme, or following the system, and the app language if you picked one yourself;
  • flags recording that you have been through the intro screens and that the app has asked for the notification permission;
  • the expiry time of an ad-free break, if you watched a rewarded ad to get one;
  • a simple counter that decides when the app offers to ask for a review.

This data:

  • is never sent to us or to anyone else;
  • may be included in your account's Google backup (Android Backup) if app backup is enabled on your device — that backup is managed by Google and accessible only to your account;
  • is removed entirely when you clear the app's data or uninstall the app.

Third-party advertising (Google AdMob)

The app is free and funded by ads served through Google AdMob, a service of Google LLC. To serve and measure ads, Google as a third-party provider may collect and process data from your device, including:

  • the Advertising ID (AAID) — an advertising identifier you can reset at any time;
  • the IP address and the coarse location derived from it;
  • device information such as model, operating system version, language and mobile carrier;
  • ad interactions such as which ads were shown, viewed or clicked.

That data is collected directly by Google, not by us, and is subject to the Google Privacy Policy. A more detailed explanation is available in How Google uses information from sites or apps that use our services. The ad SDK receives none of your answers, scores or session history.

For users in the European Economic Area, the United Kingdom and Switzerland, the app shows Google's consent form (User Messaging Platform) before any ad loads. Your choice there decides whether Google may serve personalised ads, and you can change it again from the Settings screen inside the app.

The app also offers a rewarded ad: one row in Settings trades a single short ad for 5 minutes without ads. Watching is always your choice — no feature is locked behind it.

Daily practice reminder

If you switch it on in Settings, the app schedules one notification a day at the time you chose. The schedule is stored and run by the Android system on your device — no push service, device token or server is involved. On Android 13 and above, the app asks for the notification permission only when you switch the reminder on; if you decline, the reminder stays off and every other feature works as before.

App permissions

Permissions the app requests directly:

  • android.permission.INTERNET — loading ads.
  • com.google.android.gms.permission.AD_ID — access to the Advertising ID for advertising purposes.
  • android.permission.POST_NOTIFICATIONS — showing the daily practice reminder, only if you switch it on.
  • android.permission.RECEIVE_BOOT_COMPLETED — setting the reminder schedule again after the device restarts, because Android clears scheduled alarms when the device powers off.

The following permissions are added automatically by the libraries the app uses, and are used only by those libraries:

  • android.permission.ACCESS_NETWORK_STATE — checking that a connection exists before loading an ad.
  • android.permission.WAKE_LOCK and android.permission.FOREGROUND_SERVICE — used by the Google libraries that ship inside the app (the ads SDK and its supporting libraries) for their own background work.
  • android.permission.ACCESS_ADSERVICES_AD_ID, ACCESS_ADSERVICES_ATTRIBUTION, ACCESS_ADSERVICES_TOPICS — the Android Privacy Sandbox advertising APIs on Android 13 and above.
  • com.android.vending.BILLING — added by the Google Play Billing library that ships inside the app's shared modules. Math Drill sells nothing: there is no product, no payment screen, and no payment data is processed.

The app requests no storage, camera, microphone, location or contacts permission, and no other sensitive permission.

Your choices

  • Turning off personalised ads. Open Settings › Google › Ads on your Android device and turn on "Opt out of Ads Personalisation" or delete the Advertising ID. Ads will still appear, but they will no longer be personalised. Users in Europe can also change their ad consent choice from the Settings screen inside the app.
  • Resetting the Advertising ID. From the same menu, you can reset the advertising identifier at any time.
  • Using the app without a connection. Every practice feature works fully offline. With no connection, no ads are loaded.
  • Turning the reminder off. The daily reminder is off by default and can be switched off again at any time from Settings inside the app, or from Android's notification settings.
  • Resetting your level. The "Reset level" row in Settings sends the adaptive level back to the start without deleting your session history.
  • Deleting all your data. Since everything is stored locally, clearing the app's data (Settings › Apps › Math Drill › Storage › Clear data) or uninstalling the app permanently removes your whole history and every setting. There is no copy left on our side, because we never received it.

Children's privacy

The app is a general mental arithmetic trainer and is not directed at children under 13. We do not knowingly collect personal data from children. If you are a parent or guardian and believe your child has provided personal data to us, please contact us at the address below.

Security

All connections to the ad network use HTTPS. Because the app sends no practice results and no personal data to any server, there is no copy of your data on our side that could leak. Your history and settings live in the app's private space, isolated from other apps by the Android operating system.

Changes to this policy

This privacy policy may be updated from time to time, for example when a feature or a third-party service changes. The latest version is always published on this page with a new update date.

Contact

Questions about this privacy policy can be sent to admin@gookkis.com.