Effective 18 May 2026
This privacy policy covers all games published by Isak Karlsson under the games.isak.tech umbrella. Each game has its own subsection below describing data collection specific to that game. We collect the minimum necessary, sell nothing, and use no third-party analytics or advertising SDKs.
Across every game we publish:
Sudoku integrates with Apple's StoreKit for an optional in-app subscription (Sudoku Premium). When you subscribe, Apple shares the following with our server-side subscription validator:
If you do not subscribe, no data is sent to our servers.
Sudoku also stores game state — current puzzle, pencil marks, highlights, undo history, completion times — entirely on your device in iOS application storage. None of this leaves your phone.
The original transaction ID is used solely to answer one question: is this Apple ID currently a paid subscriber, so should they be allowed to download archive puzzles? That's the entire purpose. We do not build user profiles, segment audiences, or run analyses on this data.
Our subscription validator runs on AWS Lambda in the us-west-2 region. Subscription state records are stored in an Amazon S3 bucket in the same region, encrypted with AES-256 at rest, with all public access blocked. Records are keyed by Apple's original transaction ID and do not contain your name or email.
We retain subscription state records for the lifetime of your subscription plus seven years thereafter, as required by United States tax and accounting regulations. You can request deletion of inactive (expired) subscription records by contacting privacy@isak.tech.
Sudoku Premium is offered as an auto-renewable subscription. Two subscription lengths are available:
Prices may vary by country in accordance with Apple's pricing matrix.
Payment will be charged to your Apple ID account at the confirmation of purchase. Your subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. The cost of renewal will match the original subscription price unless price changes are communicated to you in advance.
You can manage and cancel your subscription by going to Settings → [your name] → Subscriptions on your device after purchase.
Any unused portion of a free trial period will be forfeited when you purchase a subscription, where applicable.
Sudoku Premium is shareable with up to five family members via Apple's Family Sharing.
Under GDPR, CCPA, and similar legislation, you may have the right to:
To exercise any of these rights, or to ask any question about this policy, email privacy@isak.tech.
If we change this policy, we will update the effective date at the top. Material changes — anything that expands the categories of data collected or how it is used — will be announced inside the app at least 30 days before taking effect.