Last updated: April 8, 2026
CheesCoach is a chess coaching application for Android developed by JuanfranDevs. This privacy policy explains how our application handles your data. We are committed to protecting your privacy and being transparent about our data practices.
Key principle: CheesCoach is designed to be privacy-first. All your chess data is stored locally on your device. We do not collect, store, or transmit personal information to our servers — because we don't have any.
CheesCoach is offline-first: the core features (playing, puzzles, move review, Stockfish analysis, importing/exporting PGN) work without an internet connection and store everything locally on your device. No personal data is collected for these features.
Some optional online features (AI coaching via our backend, online play via Lichess) transmit limited data to third parties. These features are described in sections 3 and 4 below and can be disabled at any time.
| Data Type | Purpose | Storage |
|---|---|---|
| Chess games (PGN) | Saving and reviewing your games | Local database (Room) |
| Move analysis | Caching AI analysis to avoid repeated API calls | Local database (Room) |
| API keys | Authenticating with AI providers you choose | Encrypted (AES-256-GCM) |
| App preferences | Theme, ELO level, board colors | DataStore Preferences |
| Puzzle progress | Tracking your puzzle rating and streaks | DataStore Preferences |
CheesCoach offers optional AI-generated chess commentary. There are two independent ways to use it and you choose which one.
By default, every user gets 5 free AI analyses. Additional analyses require credits, which can be purchased inside the app via Google Play Billing. In this mode, your requests go through our backend hosted on Supabase (EU region), which forwards the chess data to the AI provider on your behalf.
To use Mode A you must sign in with Google, because we need a stable identifier to track your free-call and credit balance across reinstalls. We store the following on the backend:
The AI providers used by the backend are DeepSeek (primary) and Google Gemini 2.5 Flash (fallback if DeepSeek is unavailable).
Data residency notice: DeepSeek is a Chinese company and processes requests on servers located in the People's Republic of China. The backend only sends non-personal chess data (FEN position, move history in PGN, Stockfish evaluation, coach ELO). Your Google email is NEVER included in the AI provider request — the backend uses it only internally to look up your credit balance. If you prefer to avoid DeepSeek entirely, you can use Mode B (your own API key) or contact us to request DeepSeek be disabled for your account. An administrative kill switch also lets us disable DeepSeek instantly and route all traffic to Gemini (EU) if needed.
If you have your own API key from a supported AI provider, you can configure it in Settings and the app will call the provider directly from your device, completely bypassing our backend. This mode does not require a Google account, does not consume credits, and does not involve any of our servers.
When you use the AI coaching feature, the following chess-specific data is sent to your chosen AI provider:
No personal information is ever sent to AI providers. Only chess positions and game data are transmitted. Your API key is sent as an authentication header but is never shared with us.
Important: Each AI provider has their own privacy policy governing how they handle data sent to their APIs. We encourage you to review the privacy policy of your chosen provider. CheesCoach has no control over how third-party AI providers process the chess data sent to them.
CheesCoach offers optional online play through Lichess.org, a free and open-source chess platform.
For details on how Lichess handles your data, see the Lichess Privacy Policy.
CheesCoach does not sell or rent your personal data. Data is only transmitted in the following cases:
The app contains no ads, no trackers, and no analytics SDKs.
CheesCoach does not knowingly collect any personal information from children under 13 years of age. Since the app does not collect personal data from any user, it is safe for children to use. However, if a child uses the optional AI coaching or online play features, data will be transmitted to third-party services as described above.
Parents or guardians should be aware that the AI coaching feature involves third-party AI providers and, in Mode A, in-app purchases via Google Play Billing. We recommend parental supervision and enabling Google Play parental controls for this feature.
You retain full control over your data. Under GDPR (if you are in the EU) you have the rights of access, rectification, erasure, restriction, portability, and objection with respect to any data we store about you. To exercise any of these rights, contact us using the details in section 10.
We may update this privacy policy from time to time. Any changes will be posted on this page with an updated revision date. We encourage you to review this policy periodically. Continued use of the app after any changes constitutes acceptance of the updated policy.
If you have any questions or concerns about this privacy policy, please contact us: