Privacy Policy

Effective Date: January 1, 2025

Kyusung Lee ("Developer") operates the Sudoku mobile application ("App"). This Privacy Policy explains what information the App collects, how it is used, and your rights regarding that information.

1. Information We Collect

The App may collect the following information:

Device information: Device model, operating system version, and app version for crash reporting purposes.
App usage data: Screen views, feature usage patterns, and session duration collected anonymously via Firebase Analytics.
Crash reports: Technical error data collected via Firebase Crashlytics to help us improve app stability.
Game data: Your puzzle progress, statistics, and settings are stored locally on your device only and are not uploaded to our servers.
Anonymous user ID: An anonymous identifier (uid) generated via Firebase Authentication, stored on our servers (Firebase/Cloud Firestore) to recognize your device and provide features such as feedback replies.
Push notification token: A Firebase Cloud Messaging (FCM) token used to deliver push notifications (e.g., replies to your feedback), stored on our servers (Cloud Firestore).
Feedback content: When you submit an inquiry or suggestion, the title and content you enter are stored on our servers (Cloud Firestore) so we can review and respond.
Error and crash logs: When an error occurs, technical details (error type, error message, device information, and app version) are stored on our servers (Cloud Firestore) to help us diagnose and fix problems.

2. How We Use Your Information

To identify and fix crashes and bugs (Crashlytics)
To understand how the App is used and improve the experience (Analytics)
To serve relevant advertisements (Google AdMob)

3. Third-Party Services

The App uses the following third-party services:

Firebase Analytics (Google): Anonymous usage analytics. Data retained up to 14 months per Google policy.
Firebase Crashlytics (Google): Crash and error reporting. Data retained per Google policy.
Google AdMob: In-app advertising. Google may use advertising identifiers (IDFA/GAID) for ad personalization.

Each third-party service has its own privacy policy. We encourage you to review them: Google Privacy Policy .

4. Data Storage

Your game data (puzzle state, statistics, and settings) is stored locally on your device using your device's storage, and this game data is not uploaded to any server. Uninstalling the App will delete all locally stored game data.

Separately, certain data is stored on our servers (Firebase/Cloud Firestore): your anonymous user ID (uid), your push notification (FCM) token, any feedback you submit (title and content), and error/crash logs (error type, error message, device information, and app version). This server-stored data is retained per Google's Firebase data retention policies and is used only to operate and improve the App.

5. Children's Privacy

The App is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided personal information, please contact us and we will delete it.

6. Your Rights

Depending on your location, you may have the right to access, correct, or delete your personal information. Since game data is stored locally on your device, you can delete it at any time by uninstalling the App or clearing app data in your device settings.

For analytics data held by Google, you can opt out of analytics tracking through your device settings (Limit Ad Tracking on iOS / Opt out of Ads Personalization on Android).

7. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated effective date. Continued use of the App after changes constitutes acceptance of the updated policy.

8. Contact

Developer: Kyusung Lee (이규성)

App Name: Sudoku

Email: leekyusung1031@gmail.com