Chess Puzzles — Privacy Policy

Last updated: 19 May 2026

This Privacy Policy describes how the Chess Puzzles mobile application (the "App") handles user information. The App is developed and operated by deve.net.

1. Information We Collect

The App uses Firebase Authentication and Cloud Firestore (services provided by Google) to enable optional leaderboard features. The following data is stored on Firebase servers:

Data stored on Firebase servers

  • Anonymous user ID — A random identifier generated by Firebase Authentication. It is not linked to any personal account: no email, no name, no phone number is required or collected.
  • Nickname — Only stored if the user voluntarily chooses to set one. No verification or personal information is required.
  • Rating and puzzle count — The user's current ELO rating and total number of solved puzzles, used to determine leaderboard rankings.
  • Country code — A two-letter ISO country code (e.g. "TR", "US"), automatically detected from the device's SIM card or system locale. Used to populate the country-specific leaderboard.

Data that stays on the user's device only

  • Puzzle history and statistics
  • Favorite puzzles
  • Achievement progress
  • App preferences (theme, language, sound, notifications)
  • Rating history graph data

2. Optional Participation

The App can be used without setting a nickname. Leaderboard features are optional and users may opt out by simply not choosing a nickname. No personal account or sign-up is required at any point.

3. Data Security

All data transmitted between the App and Firebase is encrypted in transit using TLS/HTTPS. Firebase services follow Google's industry-standard security practices.

4. Third-Party Services

The App relies on the following Google services:

  • Firebase Authentication — Used solely for anonymous sign-in to enable leaderboard participation. See Firebase Privacy and Security.
  • Cloud Firestore — Stores leaderboard data (nickname, rating, country code, anonymous user ID).

No data is shared with advertising networks, analytics platforms, or any third party.

5. Internet Access

The App functions almost entirely offline. The full puzzle database (50,000+ puzzles) is bundled within the App. An internet connection is used only for:

  • Submitting the user's rating to the leaderboard after solving a puzzle
  • Fetching leaderboard rankings when the user opens the leaderboard screen

6. Permissions

The App requests the following Android permissions:

  • Internet — Required for Firebase leaderboard synchronization.
  • Notifications (optional) — For local reminders about daily puzzles and streaks. No data is transmitted; notifications are generated entirely on the device.
  • Vibrate — For haptic feedback when making chess moves.

7. Children's Privacy

The App is suitable for all ages and is rated PEGI 3 / Everyone. No personal identifying information is collected from any user, regardless of age. The optional nickname field accepts any user-provided text and is subject to a built-in profanity filter.

8. Data Deletion

Users may request deletion of their leaderboard data at any time by contacting contact@deve.net. Since the data is anonymous, the user should provide either:

  • Their nickname (as it appears on the leaderboard), or
  • Their anonymous user ID (visible in the App's settings or upon request)

Deletion requests are processed within 30 days.

9. Data Retention

Leaderboard data is retained indefinitely as long as the user continues to play. If the user uninstalls the App without requesting deletion, the anonymous record may remain on Firebase indefinitely but is not linked to any personal information.

10. Puzzle Source

All puzzles in the App are sourced from the Lichess.org puzzle database, released under the CC0 1.0 Universal Public Domain Dedication. No data is sent to Lichess.org.

11. Changes to This Policy

If this Privacy Policy is updated, the revised version will be posted at this URL with a new "Last updated" date. Significant changes will be communicated through the App or via the Google Play Store changelog.

12. Contact

Questions, concerns, or data deletion requests can be sent to:

contact@deve.net

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