Privacy policy
Last updated 17 September 2026.
Sudoku Nine is made by PikeWorks, one person in Northern Ireland, the developer named on its Google Play listing. This page says what the app keeps, what leaves your phone, and why.
What stays on your phone
Your puzzles, games in progress, settings, profiles, statistics and achievements are stored in the app's private storage on your phone. There is no Sudoku Nine account and no Sudoku Nine server, so none of it is sent to the developer. Puzzles are made on the phone and the daily puzzle is worked out from the date.
A backup file or a CSV export is only created when you tap to make one, and it goes wherever you choose to send it.
Adverts
The Android app shows adverts from Google AdMob, through the Google Mobile Ads SDK. They never appear on the puzzle board. To serve and measure adverts, and to prevent fraud, Google receives information from your phone that can include:
- your IP address, from which an approximate location can be worked out;
- your phone's advertising ID and app set ID;
- device details such as the model, operating system and language;
- which adverts were shown and tapped;
- diagnostic information about how the adverts loaded.
In the UK, the European Economic Area and Switzerland, Sudoku Nine asks through Google's consent message whether adverts may be personalised before any are requested. In US states with their own privacy laws you can opt out of the sale or sharing of your information. Either way you can change your answer at any time under Settings, Privacy choices. If you do not agree, adverts are still shown but they are not personalised.
You can also reset or delete your advertising ID in your phone's settings, under Google, Ads. How Google uses this information is described at policies.google.com/technologies/partner-sites.
If you buy Nine Complete or Remove adverts, the app stops requesting adverts.
Purchases
Nine Complete and Remove adverts are one-off purchases processed by Google Play. The purchase is checked by RevenueCat, which receives an anonymous app user ID and the purchase receipt so that it can confirm what you bought and restore it on another phone. The developer never sees your name, email address or payment details. RevenueCat's policy is at revenuecat.com/privacy.
Permissions
Sudoku Nine uses the internet only for adverts and purchases. It does not ask for your location, contacts, camera, microphone or photos.
Children
Sudoku Nine is intended for adults and is not directed at children.
Deleting your information
Uninstalling Sudoku Nine deletes everything it stored on your phone. The developer holds no copy. For information Google holds about adverts, reset or delete your advertising ID and use the controls in your Google account.
Changes
If this policy changes, the date at the top changes and the new version replaces this one.
Contact
Email the developer address shown on the Sudoku Nine Google Play listing.