Privacy Policy — Chess Openings Trainer

Effective date: August 16, 2026
Developer: Connor Cunningham (“we”, “us”)
Contact: connor.cunningham7237@outlook.com

What this app does

Chess Openings Trainer helps you learn and practice chess openings using spaced-repetition training. You can use the core features without an account; an optional free account adds sync across devices.

Information we collect

Without an account: your repertoires, training lines, and review history are stored only on your device (local database). We do not receive them.

With an account (optional):

• Email address — used to create and authenticate your account.
• Training data — your repertoires, opening lines, review history, learning progress, and streaks, stored in our database (hosted on Supabase) so they sync across your devices.
• chess.com and/or Lichess username (optional) — if you connect an account, we fetch your public games from that site's public API to analyze your openings and suggest lessons; the username and derived insights are stored with your account. Connect either site or both; disconnecting one in Settings removes that site's games and analysis without touching the other.
• Push notification token and device timezone (optional) — if you turn on the daily training reminder and grant notification permission, the app stores a push delivery token and your device's timezone with your account so our server can send you one evening training note at a sensible local hour. The token is deleted when you sign out, and reminders can be turned off any time in Settings. Notifications are delivered via Expo's push service, which receives only the token and the message.

With a subscription (when available): purchases are processed by Apple App Store or Google Play; we never see your payment details. Our subscription processor (RevenueCat) and our database receive your subscription status (active/expired, product, expiry date) tied to your account id so the app can unlock premium features.

Diagnostics and analytics: the app reports crashes and errors to Sentry (crash diagnostics) and a small set of product events — such as completing onboarding, connecting chess.com, finishing a session, seeing the paywall, or completing a purchase — to PostHog (product analytics), in each case tied to your account id when you are signed in. This helps us find crashes and understand which features work. Neither service is used for advertising, and we do not share this data for advertising or cross-app tracking.

We do not collect: location, contacts, photos, or advertising identifiers. The app contains no ads and no advertising or cross-app tracking SDKs.

How we use information

• Provide and sync the training features you use.
• Determine subscription entitlement.
• Respond to support requests you send us.

We do not sell personal information, and we do not share it with third parties except the service providers above (Supabase for data hosting and authentication, RevenueCat and the app stores for subscriptions, Sentry for crash diagnostics, and PostHog for product analytics), each acting on our behalf.

Data retention and deletion

Your synced data is retained while your account exists. You can delete your account and all associated data directly in the app (Settings → Delete account), or contact connor.cunningham7237@outlook.com from the account’s email address. We aim to complete emailed deletion requests within 30 days.

Local-only (signed-out) data is removed when you uninstall the app.

Security

Data in transit is encrypted (HTTPS). Database access is restricted per-user (row-level security): your data is readable and writable only by your authenticated account.

Children

The app is not directed at children under 13, and we do not knowingly collect personal information from them.

Changes

We will post any changes to this policy at this URL and update the effective date. Material changes will be noted in the app’s release notes.

Contact

Questions or requests: connor.cunningham7237@outlook.com