MentoChess (“the app”) is a chess training app published by Derovest (“we”). This policy explains what the app stores, what it sends and to whom, and the choices you have. In short: your chess data stays on your phone unless you choose to create an account, we show no ads, and we never sell your data.
Data stored on your phone
Your profile (the name you enter, your level and goals), your linked Chess.com and Lichess usernames, your downloaded games and their engine analysis, your training history, your answers to the coach, your tournament records and your settings are stored only on your device. Game analysis runs on your device with the Stockfish engine. You can delete all of it at any time in You → Preferences → Delete all data, or by uninstalling the app.
Data the app reads from other services
- Chess.com and Lichess: the app downloads your public games and ratings using the usernames you enter. No password is requested. When you use opponent preparation, it downloads the public games of the username you enter.
- FIDE: if you enter a FIDE ID, the app reads your public rating profile from ratings.fide.com.
These requests go directly from your phone to those services and are subject to their own privacy policies.
Optional account and backup
You can sign in with Google or with a code sent to your email. With Google, Google shares your name, email address and profile picture with us; we use them only to identify your account and show who is signed in. If you create an account, we collect your email address, and we store a backup of your app data (the data listed above) in a private storage area that only your account can read. Accounts and backups are hosted by Supabase (supabase.com) on our behalf. Accounts are intended for users aged 13 and over; younger players can use the app without an account.
AI coach (account required)
When you choose to tell the coach in your own words what you were thinking, the text you write and the facts about that chess position (the moves and the engine's evaluation) are sent through our server to Google, which provides the Gemini AI model that writes the reply. We record how many AI replies you used each month, to apply the fair-use limit. We do not attach your name or email address to these requests. We ask Google not to store the request after replying, and under Google's paid API terms it is not used to train or improve Google's models.
Purchases
MentoChess currently has no purchases; every feature is free. If we introduce subscriptions, they will be sold and billed by Google Play, and we will update this page before they start. We would then use RevenueCat (revenuecat.com) to check whether a subscription is active. RevenueCat would receive purchase information from Google Play and an anonymous app user identifier (or your account identifier if you have an account). We would never see your card or payment details.
Notifications
Training reminders are scheduled on your phone. No push notification service is used, and you can turn reminders off in Preferences or in your phone's settings.
What we don't do
- No advertising and no ad networks.
- No analytics or tracking SDKs.
- No selling or sharing of your data for marketing.
Retention and deletion
On-device data is kept until you delete it. Account data (email, backup, Premium status, AI usage counts) is kept until you delete your account, which you can do in the app (You → Account & backup → Delete my account) or by following these steps. Deletion removes the account and all data stored with it.
Children
The app can be used without an account or any personal information. We do not knowingly collect personal information from children under 13; if you believe a child has created an account, contact us and we will delete it.
Your rights
You can access, correct or delete your data at any time from the app, or by contacting us. Depending on where you live (for example the EU, UK, India or California), you may have further rights under local law, and we will honour them.
Changes and contact
We will update this page if the app's data practices change. Questions: hello@derovest.com.