Privacy policy

Camera and coaching on iPhone and iPad

Camera access is used to recognize Sudoku grids and place AR hints. Camera images are processed on your device. Scanning may temporarily keep a cropped grid image in memory so you can check uncertain digits against a frozen image; image data is also used in memory for AR tracking. The app does not upload these images or write them to your photo library or persistent app storage.

The AR Coach checks Sudoku logic locally. The optional AI Coach also generates replies on your device. Your chat messages, selected puzzles and generated replies are not sent to a cloud AI service or used by this app to train a model.

AI Coach requires a model download, currently approximately 2.84 GB. The app shows the download size and installation-space requirement before asking you to download it. The large model transfer requires your approval and does not use cellular data. Use Wi-Fi for this transfer. You can choose Not now or cancel the transfer.

After setup, the verified model is stored on your device for offline use and excluded from device backups. This download is not required for ordinary Sudoku games, scanning or the AR Coach.

Online services on iPhone and iPad

The app uses Google Firebase Storage to check model metadata and download the AI Coach model. The approved model name and verification fingerprint are included in this app version; it does not use Firebase Remote Config. It does not upload your saved puzzles or conversations to Firebase.

If a model download is needed, opening AI Coach can make small metadata requests before you decide whether to download. Download or Not now controls the large transfer, not those initial requests. A previously downloaded, verified model can be used offline.

These requests expose network information such as your IP address to the service. Firebase may also process technical app, device, OS and SDK information and service diagnostics to operate and improve its services.

Firebase service data is handled by Google under its service and privacy terms, including its retention practices. This app does not include advertising or use Firebase Analytics to track your behaviour.

For more information, see Firebase privacy and security information and Firebase’s Apple-platform data disclosures.

Native visionOS app

Puzzle progress and preferences are stored on your Apple Vision Pro. Puzzle generation, checking and coaching run locally. This version does not use the camera, download an AI language model or connect to Firebase.

The app does not send your puzzle contents or usage to the developer. External links in the app open external services only when you choose to open them. The visionOS app keeps its own progress; it does not import or sync games from the iPhone or iPad app.

Local storage, backups and your choices

On iPhone and iPad, saved games, playing history, statistics and preferences are stored locally. Saved game data can include puzzle digits, notes, moves, mistakes and playing times. AI Coach stores up to ten recently updated conversations, including your messages, generated replies and selected puzzle data. You can delete individual conversations in AI Coach; deleting a conversation does not delete separately stored games, history or statistics.

On visionOS, puzzle progress, notes, undo history and preferences are stored locally. Starting a new puzzle replaces the current puzzle, but is not a command to erase all app data. Local history and other app data remain until removed; deleting the app is the way to remove all of its local data.

System backups may contain local app data, depending on your Apple backup settings. The downloaded iOS AI Coach model is excluded from backups. Backup handling is separate from the app’s lack of a cross-device syncing service.

• You can revoke camera access in iPhone or iPad Settings and continue using non-camera game features.
• You can decline or cancel the optional model download without losing ordinary gameplay or AR Coach access.
• You can delete individual conversations in AI Coach. Older conversations beyond the ten most recently updated are removed from that stored conversation list.
• Deleting the app, rather than offloading it, removes its local app data, including its downloaded model. Device backups are managed separately in your Apple settings.

Contact and external links

If you contact support, Alban Tiacoh receives the information you choose to send and uses it to respond. Only attach photos, diagnostic information or conversation content if you want to share them. Do not send sensitive personal information.

Support emails and any attachments retained for troubleshooting are deleted once the issue is resolved. Email providers may retain backup or service records under their own policies.

External websites and email providers have their own privacy practices. Opening the support website or sending an email involves those services, independently of the app’s on-device puzzle processing.

For privacy questions or to request deletion of information you sent to support, email alban@cambrien.com. The publisher cannot remotely access or delete app data stored only on your device; use the local choices described above.

For help using the app, visit the Sudoku AR support page.

Changes to this policy

This page may be updated when the app’s features or data handling change. The date at the top identifies the latest update. Check the version-specific descriptions when using an older release.