_Last updated: 16 October 2026_
Sudoku Koan is a puzzle game that works fully on your device. We do not ask for an account, your name, email address or contacts.
Your puzzles, progress, statistics, streaks, achievements and settings are stored only on your device. You can export them as a file from Settings → Export backup. Uninstalling the app deletes them.
The free version shows ads from Google AdMob — a banner on the home and results screens and a full-screen ad between puzzles — and offers optional rewarded videos. AdMob may collect device identifiers and approximate location to show and measure ads. In the EEA, UK and Switzerland we ask for your consent first (Google's consent form); you can change your choice at any time in Settings → Privacy options. On iOS we do not request tracking permission, so ads are not personalised with data from other apps. Google's policy: https://policies.google.com/technologies/ads
Subscriptions and the remove-ads purchase are processed by Apple or Google and managed through RevenueCat, which receives an anonymous app user ID and your purchase history — never your payment details. RevenueCat's policy: https://www.revenuecat.com/privacy
Google Firebase Analytics records how the app is used (events such as "puzzle solved", with an app-instance identifier and device information) and Firebase Crashlytics sends crash logs and diagnostics, so we can fix bugs and improve the app. This data is never used for advertising, and no name, email or puzzle content is included. Google's policy: https://firebase.google.com/support/privacy
Sudoku Koan is not directed at children under 13 and does not knowingly collect personal information from them.
Questions about privacy: infivlabs@gmail.com.