ChessDuoLast updated: September 26, 2026
Who we are
ChessDuo is published by Michael Shobitan and its online features run on Berth. Contact: hello@atberth.com.
Games on one phone
Pass & Play, Play the Computer, Puzzles, Learn and the Analysis Board run on your device. The chess engine and coach for these modes work offline, and nothing about these games is sent anywhere unless you sign in to back them up (see Optional account).
What the app collects when you play online
When you play online, the app sends only what is needed to run a match:
- The display name you type (for example Mike or Lily)
- Room codes, moves, draw or undo requests, nudges, and match results
- A random player token stored on your phone so you can rejoin your games
- If you allow notifications, your device's push token and whether turn alerts are on, so the app can tell you when it's your turn
Settings you choose, such as language, board theme, and whether hints are on, stay on the device unless you sign in.
If you use hints or coaching tips in an online game, the server may send the position to an AI provider (OpenRouter or OpenAI) so it can suggest a move or a short lesson. That request is the game position, the legal moves, the players' display names and the language, not your Apple ID, email, contacts, or photos.
Optional account
You don't need an account to play. If you choose to sign in with Apple, Google, or email and password or an emailed code, we store your email address and the name you give, so you can sign in on another device. While you are signed in, the app backs up your past games, stats, puzzle progress, settings, current room and recent room codes, so they restore on a new phone. The Account screen shows the devices signed in to your account and lets you sign them out.
Where it is stored
Live games, past-match scorecards, push tokens and account backups are stored on Berth (a hosted backend) so both phones can see the same board. Settings, your game history and the player token are also stored on your device. Account sign-in details are kept in the iOS Keychain.
What we do not collect
- No advertising ID, no tracking across other apps
- No ads, no analytics SDKs, no crash reporters that identify you
- No camera, microphone, photos, contacts, or location
Children
ChessDuo is meant for beginners of any age playing with someone they know. Do not type a real last name, email, or address into the name field. Use a first name or a nickname.
Retention and deletion
Match data is kept so you can open Past games. If you signed in, you can delete your account in the app from the Account screen. That removes your account and the games, stats and settings backed up to it. If you want a shared game or other stored data removed, email hello@atberth.com with the room code. Deleting the app from your phone removes the local token and settings. It does not automatically erase the server copy of a shared match.
Changes
If this policy changes, the date at the top will change. The latest version will always be at this URL.