日本語

Crazy Math Master Privacy Policy

Last updated: October 20, 2026

"Crazy Math Master" (the "App") is a mental-arithmetic practice app for children. This policy explains how the App handles your information. The Japanese version of this policy is the official text; this English version is provided for convenience.

1. Information collected by the App itself

The App does not collect personal information such as your name, e-mail address or location. There is no account registration.

Study records (questions answered, right or wrong, study time, test results, streaks and settings) are stored only on your device. They are never sent to the developer or to any third-party server. You can delete the records yourself with "Delete study data" on the settings screen.

2. Advertising

The App shows no ads, on either the Android version (Google Play) or the iOS version (App Store). It contains no ad-delivery component (ad SDK) and does not use the device's advertising ID.

3. In-app purchases

The App offers Premium per level as a one-time in-app purchase. Payment is handled by Google Play or the App Store; the App never receives payment details such as credit-card numbers. Purchase records are tied to your Google Play / App Store account and can be restored on a new device with "Restore purchases" on the settings screen.

4. Notifications

Study reminders are shown by the device itself (local notifications) on the days and at the time you set on the settings screen. No network communication or data transfer is involved. You can stop them at any time with the switch on the settings screen or in the device settings.

5. Rating the App and Feedback

You can rate the App from "Rate this app" in Parent settings, which opens the App's page on Google Play or the App Store. A check for parents (entering the answer to a calculation) is shown before Parent settings opens. The App never shows rating requests on its own. Ratings and reviews are handled by the store; the App does not receive their content.

"Send feedback to the developer" in Parent settings creates an email to the developer in your device's email app. To help investigate problems, the email body is pre-filled with the App's name and version, the display language, and the device's OS type and version (you can review or delete them before sending). The email reaches the developer only if you send it; the sender's email address and the content are used only to reply to inquiries and improve the App, and are not shared with third parties.

6. Network use

All study features work without a network connection. The App communicates only for in-app purchases and app ratings (Google Play / App Store). Feedback emails are sent from your device's email app.

7. Children's privacy

The App is intended mainly for children. The App itself does not collect personal information from children. The App shows no ads. Parents and guardians should review this policy regarding in-app purchases before use.

8. Changes to this policy

Changes to this policy are published on this page. Important changes are also announced on the App's store page.

9. Contact

For questions about this policy or the App, please contact: