Last updated: 26 August 2026
OpeningBook (“the app”) is a chess-opening reference and trainer. In short: the app collects no personal data and works entirely offline.
None. There are no user accounts, no analytics, no advertising, and no third-party tracking of any kind.
Your training progress and preferences are stored only on your device. This information never leaves your device and is not accessible to us. Deleting the app removes it.
The app is fully offline. It bundles all opening data locally and makes no network requests during normal use.
OpeningBook offers a one-time in-app purchase to unlock the training feature. Purchases are processed entirely by Apple through the App Store. We do not receive, see, or store your payment details.
The app is suitable for all ages and collects no data from anyone, including children.
The app bundles chess opening data from the Lichess openings database (public domain, CC0) and chess piece images from the “cburnett” set (CC BY-SA 3.0). These are static, bundled assets and collect no information.
If this policy changes, the updated version will be posted at this URL with a new date.
Questions about this policy: zhenghongpengcs@gmail.com