Sudoku Privacy Policy

1. Scope and privacy summary

This Privacy Policy explains how the developer of Sudoku (“we”, “us”, or “the developer”) handles information in the Sudoku mobile applications (“Sudoku” or “the app”). Sudoku is a classic, primarily offline puzzle game. It does not require an account, login, social profile, ranking, or cloud synchronization.

2. Information stored locally

The following information may be stored in private app storage so Sudoku can work offline and restore your experience:

• puzzle and session identifiers, given digits, entered digits, candidate notes, undo and redo state, elapsed time, mistakes, hints, and completion state;
• local game results, completion history, best and average times, and aggregate statistics;
• a locally selected nickname and avatar;
• appearance, language, sound, vibration, input, highlighting, reminder, accessibility, and privacy preferences; and
• your privacy choice, the policy version shown, and the time and source of that choice.

This local information is not uploaded merely because you play a puzzle. It remains until you remove it through an available app control, clear the app’s storage, or delete the app. Operating-system backup behavior is controlled by the platform and your device settings where applicable.

3. Network requests

Sudoku includes built-in puzzles so the basic game works without a network connection. When the app requests additional puzzle content or checks service availability, our API and hosting providers may process ordinary technical metadata such as IP address, request time, route, response status, app version, and security information needed to deliver and protect the service. We do not require an account identifier for classic Sudoku play.

4. Firebase Analytics and Crashlytics

After you explicitly choose Agree and continue, Sudoku may initialize the following Google Firebase services:

• Firebase Analytics may process app interaction events, app and device information, approximate technical location derived from network information, language, app version, operating-system version, and Firebase-generated installation or app-instance identifiers. We use this information to understand feature use and improve the app.
• Firebase Crashlytics may process crash reports, stack traces, diagnostic logs, device and operating-system information, app version and state, crash time, and Firebase-generated installation identifiers. We use this information to diagnose crashes and improve stability.

These services are provided by Google LLC and may process data on infrastructure outside your country or region under Google’s terms and privacy practices. Sudoku does not use Firebase Analytics for personalized advertising, does not intentionally collect the Android advertising ID for these services, and does not request Apple App Tracking Transparency permission merely to provide analytics or crash reporting. Learn more in Google’s Privacy Policy.

If you choose Disagree, Firebase Analytics and Crashlytics remain disabled and the app closes. The declined choice is not treated as permission and is not used to initialize either service. If you previously agreed and later want to withdraw that authorization, clear Sudoku’s app storage or delete the app as described on the Data Deletion page. Withdrawal does not retroactively erase processing lawfully completed before withdrawal or data that Google must retain for security or legal reasons.

5. Advertising and tracking

The current release does not integrate or initialize TopOn or another advertising SDK. If a future release adds advertising or another materially different data use, the app and this policy will be updated and any required choice will be presented before that service is initialized.

We do not sell personal information and do not use information collected by Sudoku for cross-app tracking.

6. Permissions

Sudoku may request notification permission only after you enable an unfinished-game reminder. The current classic game does not require precise location, contacts, call logs, SMS, nearby devices, camera, microphone, health data, or broad photo-library or file-storage access. System share controls process content only when you choose to share it.

7. How information is used and shared

We use information only to:

• provide, save, restore, secure, and improve classic Sudoku features;
• remember settings and the privacy choice you make;
• deliver additional puzzles or reminders that you request;
• measure app interactions after consent; and
• diagnose crashes and reliability problems after consent.

Information is shared only with service providers acting for those purposes, when you intentionally use a system sharing feature, when required by law, or when reasonably necessary to protect users, the service, or legal rights. The relevant providers currently include Google Firebase for consented analytics and crash reporting, and infrastructure providers used to host and secure app services and this website.

8. Your choices and controls

• On first installation, you can choose Agree and continue or Disagree.
• If you agree, the app stores that decision and does not ask again on every launch. If you disagree, the app closes and presents the decision again the next time it is opened.
• After agreeing, you can withdraw future authorization by clearing Sudoku’s app storage or deleting the app as described on the Data Deletion page.
• You can disable reminders in the app and manage notification permission in system settings.
• You can remove local app information as described on the Data Deletion page.

If this policy changes, the updated date and content will be published here. The current app does not automatically show the first-install choice again merely because the policy version changes.

9. Retention and deletion

Local game and setting information remains in private app storage until removed as described above. Server security logs are retained only as reasonably necessary for service delivery, reliability, abuse prevention, incident response, and legal obligations. Firebase data retention and deletion are governed by our Firebase configuration and Google’s service terms.

Sudoku does not create a user account, so there is no server-side Sudoku account to delete. For clear instructions on local deletion, consent withdrawal, and diagnostic-data requests, visit the Data Deletion page.

10. Security

Sudoku uses platform-protected app storage and HTTPS for network communication. Access to production systems is restricted and service providers are selected for operational and security needs. No storage or transmission method is completely secure, so we cannot guarantee absolute security.

11. Children

Sudoku is a general-audience puzzle game and is not directed to children under 13. We do not knowingly request a child’s name, email address, account, precise location, contacts, or other profile information. If you believe a child has provided personal information through a support interaction, contact us so we can review and delete it where required.

12. International processing

Google and other infrastructure providers may process limited information in countries or regions outside your own. Their processing is subject to applicable contractual, security, privacy, and legal safeguards.

13. Changes to this policy

We may update this policy when app features, service providers, or legal requirements change. The current version shows its last-updated date. The app remembers an accepted first-install decision and does not automatically repeat that dialog solely because this document changes. A declined decision closes the app and is presented again on the next launch.

14. Contact

Privacy contact: sd.wang.qq@gmail.com

Do not email passwords, authentication tokens, complete device identifiers, or puzzle solutions.