Privacy policy

Last updated 18 September 2026.

Sudoku Nine is made by Pikeworks, a sole trader in Northern Ireland. This is 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 kept in the app's private storage on your phone. There's no Sudoku Nine account and no Sudoku Nine server, so none of it is sent to me. 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 made 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 show and measure adverts, and to prevent fraud, Google receives information from your phone that can include:

your IP address, from which a rough 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 say no, you still see adverts, but they aren't personalised.

You can also reset or delete your advertising ID in your phone's settings, under Google, Ads. How Google uses this information is explained at policies.google.com/technologies/partner-sites.

If you buy Nine Complete or Remove adverts, the app stops asking for adverts.

Purchases

Nine Complete and Just remove adverts are one-off purchases through Google Play or the App Store. RevenueCat checks the purchase. It receives an anonymous app user ID and the purchase receipt, so it can confirm what you bought and restore it on another phone. I never see your name, email address or payment details. RevenueCat's policy is at revenuecat.com/privacy.

Permissions

Sudoku Nine only uses the internet for adverts and purchases. It doesn't ask for your location, contacts, camera, microphone or photos.

Children

Sudoku Nine is meant for adults and isn't aimed at children.

Deleting your information

Uninstalling Sudoku Nine deletes everything it stored on your phone. I don't hold a copy. For what Google holds about adverts, reset or delete your advertising ID and use the controls in your Google account.

Your rights

Sudoku Nine has no account and no server of mine, so there is nothing here for me to look up, correct or hand over: everything the app keeps is on your phone, where you can read it and delete it yourself. Where an advert or a purchase means something goes to Google or to RevenueCat, their own policies and controls cover it, and Google's advertising settings let you reset or delete the advertising ID on the phone.

Under UK GDPR you can still ask for a copy of what is held about you, ask for it to be corrected or deleted, object to it being used for personalised adverts, and complain to the Information Commissioner's Office at ico.org.uk. Personalised adverts rely on the consent you give through Google's message, and you can change that answer at any time in Settings under Privacy choices.

Changes

If this policy changes, the date at the top changes and the new version replaces this one.

Contact

Email me at hello@pikeworks.co.uk.