*Last updated: April 16, 2026*
DarkSquare Studio ("we", "us", or "our") operates the mobile application Chess: Play, Analyze, Improve (the "App"). This Privacy Policy explains what data the App collects, how it is used, and with whom it is shared.
**1. Data We Collect**
The App collects the following types of data:
- **Device or other IDs**: The App uses an anonymous app instance identifier (Firebase Installation ID) and advertising ID for analytics and advertising purposes.
- **App activity**: The App collects information about how you use the App, including screens viewed, games uploaded, games analyzed, and premium-related interactions.
- **Email address**: If you choose to sign in via Lichess OAuth, your Lichess username is stored locally on your device. We do not collect or store email addresses.
- **Purchase information**: If you make a purchase through Google Play Billing, Google processes your payment. We do not have access to your payment details.
**2. How Data Is Used**
- **Analytics**: To understand how users interact with the App and improve its functionality. We use Firebase Analytics for this purpose.
- **Advertising**: To display ads through Yandex Advertising Network. Ads are shown to free-tier users. Premium users and users who purchased "Remove Ads" do not see ads.
- **App functionality**: Lichess account linking (optional) requires OAuth authentication with Lichess.org. Your Lichess token is stored securely on your device and used only to access your Lichess account data.
**3. Third-Party Services**
The App uses the following third-party services:
- **Firebase Analytics** (Google LLC): Collects device identifiers and app usage data for analytics. [Google Privacy Policy](https://policies.google.com/privacy)
- **Firebase Authentication**: Used for Lichess OAuth sign-in. [Google Privacy Policy](https://policies.google.com/privacy)
- **Firebase Firestore**: Stores subscription tier status for authenticated users. [Google Privacy Policy](https://policies.google.com/privacy)
- **Yandex Mobile Ads SDK**: May collect device identifiers (advertising ID, Android ID) and usage data to serve relevant ads. [Yandex Advertising Network Privacy Policy](https://yandex.com/legal/partner/)
- **Google Play Billing**: Processes in-app purchases. Google handles all payment data. [Google Payments Privacy Policy](https://payments.google.com/gp/w/home/privacypolicy)
**4. Data Sharing**
We do not sell or rent your personal data to third parties. Data may be shared with:
- **Service providers**: Firebase (Google) and Yandex receive data as described above to provide analytics, authentication, and advertising services.
- **Legal requirements**: We may disclose data if required by law.
**5. Data Storage and Security**
All game analysis, chess puzzles, and user preferences are stored **locally on your device**. Chess game data is not transmitted to our servers. Lichess OAuth tokens are stored locally using Android EncryptedSharedPreferences.
**6. Children's Privacy**
Chess: Play, Analyze, Improve is intended for a general audience and is not directed at children under 13. We do not knowingly collect personal information from children.
**7. Your Choices**
- **Opt out of ads**: Purchase "Remove Ads" or a Premium subscription to remove all advertising.
- **Opt out of analytics**: You can disable ad personalization in your Android device settings (Settings > Google > Ads > Delete advertising ID).
- **Revoke Lichess access**: You can disconnect your Lichess account in the App settings or revoke access through your Lichess.org profile.
**8. Changes to This Policy**
We may update this Privacy Policy from time to time. Changes will be reflected in the "Last updated" date above.
**9. Contact Us**
If you have questions about this Privacy Policy, contact us at:
Email: ivsilan2005@gmail.com
Developer: DarkSquare Studio