Last updated: 29 April 2026
Sudoku Challenger ("we", "our", "the app") respects your privacy. This notice explains what information is (and is not) collected, how it is used, and what choices you have.
The app is available for iPhone, iPad and Mac. Some sections below apply only to one of those platforms and are marked accordingly.
We do not collect, store or process any data that can identify you. Your in-progress puzzle, timer, preferences and local rankings are stored on your device only and are never sent to us.
The "Scan a Sudoku" feature uses Apple Vision and a Core ML digit classifier that run entirely on your device. The captured or selected image is processed locally to detect the board and recognise digits. Images are not uploaded to any server, are not shared with third parties, and are not retained by the app after the scan flow ends.
You can revoke either permission at any time in iOS Settings; the rest of the app continues to work without them.
You can export a puzzle as a file (.scsdp) or as a short code and share it with anyone you choose, using the system share sheet (Mail, Messages, AirDrop, etc.). The transfer happens directly through the channel you pick — we do not host, route or see the content.
The iOS / iPadOS version displays ads through Google AdMob. AdMob may automatically gather usage data to deliver and measure ads.
The macOS version does not include advertising and does not embed any advertising SDK.
| Data handled by AdMob | Examples | Purpose |
|---|---|---|
| Device info | IP address, OS version | Deliver, tailor and measure ads |
| Usage stats | Screen views, interaction events | Improve ad relevance |
For full details, read the Google Privacy Policy.
The Service is not directed to children under 13. We do not knowingly collect personal data from minors. If you believe a child has provided data via AdMob, contact us and we will help you remove it.
Because we do not collect data ourselves, risk is limited to information processed by AdMob on iOS. Google applies technical and organisational measures to protect that data; see their policy for specifics. Data stored locally on your device is protected by the operating system's standard sandboxing and user-account isolation.
We may update this text. Material changes will appear here with a new "Last updated" date.
Questions? E-mail us at sudoku-challenger@ajgb.eu.