Privacy policy

Last updated: 17.10.2026

1. Controller

Erdi Karasungur, Bieberer Str. 52, 63065 Offenbach am Main, Germany, email: support@denkarena.com

2. Principle

DenkArena works without an account and without your name. Progress is stored on your device first. We only process data where it is needed for the app's features or where you have consented.

3. Anonymous ID and online features

For daily statistics, leagues, invites, the shop, community levels and backing up your progress, the app receives a random, anonymous ID on first launch. We store: daily puzzle results (moves, best score), league memberships and the display name you choose, invite codes (for redeemed codes also the days played during the first 14 days, so we can grant the invite reward), points and shop purchases, published levels including ratings and reports, your progress, and for online chess your player name, the moves and the result of the game (game rooms are deleted after two days; your private account archive keeps up to your last 200 completed online games, including player names, moves, results and rating changes, until you clear the archive or delete your account. Games against the computer stay on your device. For a fair play report, we also store the reporter, opponent, time, reason and a copy of the game for later review; that copy is removed when the review is closed. A limited report log is kept to prevent duplicate and excessive reports). Legal basis: Art. 6(1)(b) GDPR (providing the features you use).

3a. Profile, weekly leaderboard and reports

For your profile and the weekly leaderboard we store with your ID: display name and time of the last change, chosen avatar, frame and title, your country (derived from your device's language setting), weekly points, placings and trophies, and the “Private profile” setting. Other players see this information in the leaderboard and in your profile; with a private profile you appear there as “Anonymous” without avatar, title or profile. If you report a name, we store who reported whom and when, to prevent abuse. For online chess we also store, without reference to you, how long it took to find an opponent, to estimate waiting times (7 days). Weekly points are deleted after 8 weeks; placings and trophies stay in your profile. Messages and gifts from the DenkArena team are stored with your account. We also store which version of the terms of use you agreed to and when. Legal basis: Art. 6(1)(b) GDPR; for reports and proof of consent, Art. 6(1)(f) GDPR (protection against abuse, proof).

4. Account with email (optional)

If you back up your progress, we store your email address and send you one-time sign-in codes. So that the code email arrives in your language, we also store the app language. We use the address only for signing in, never for marketing. Code emails are sent via the email service Resend (Resend Inc., USA) with servers in the EU (Ireland). A data processing agreement is in place; possible transfers to the USA are covered by the EU Standard Contractual Clauses. Legal basis: Art. 6(1)(b) GDPR.

5. Anonymous usage statistics (can be turned off)

Without your name, we record which games are opened and finished to improve the app (e.g. whether players come back). If an error occurs in the app, we also send an error report (error message, affected part of the program, app version, device type and current screen, no content and no names). You can turn both off in the settings at any time. Legal basis: Art. 6(1)(f) GDPR (legitimate interest in improving the app). Error reports are deleted after 60 days at the latest.

5a. Feedback

If you send us a message via “Send feedback”, we store your text together with the app version, language, device type and screen size. If you have an account and allow us to reply, we also store your email address. Legal basis: Art. 6(1)(f) GDPR (handling your request). Messages we have dealt with are deleted after 180 days.

5b. Contact by email

If you write to support@denkarena.com, your message is delivered via Cloudflare’s forwarding service (Cloudflare Inc., USA) to our mailbox at Google (Google Ireland Ltd.) and stored there so we can reply. Both providers are certified under the EU-US Data Privacy Framework. Legal basis: Art. 6(1)(f) GDPR (handling your request). We delete messages once they have been dealt with and no retention obligation applies.

6. Advertising (Google AdMob)

The free version shows ads via Google AdMob (Google Ireland Ltd., Gordon House, Barrow Street, Dublin 4, Ireland). Device and advertising IDs may be processed. Personalised ads are only shown with your consent, requested on first launch and revocable at any time (Art. 6(1)(a) GDPR). Transfers to the USA are possible; Google is certified under the EU-US Data Privacy Framework.

7. Subscription (Apple, Google, RevenueCat)

Purchases are handled by the App Store or Google Play; we receive no payment data. To verify subscriptions we use RevenueCat (RevenueCat Inc., USA), which processes the anonymous ID and purchase status. We store the subscription status reported by the app (active, expiry, renewal, platform) so we can help if there are problems. Legal basis: Art. 6(1)(b) GDPR.

8. Hosting (Supabase)

Online features run on Supabase (Supabase Inc.), server location EU (Ireland). A data processing agreement is in place.

9. Notifications

Daily puzzle reminders are scheduled locally on your device; no data is sent to us for this.

10. Retention

We store data as long as you use the features. Anonymous IDs without an account that have not been used for 24 months are deleted. Usage statistics are deleted after 14 months at the latest. You can request deletion at any time.

11. Your rights

You have the right of access, rectification, erasure, restriction, data portability and objection (Art. 15–21 GDPR) and may withdraw consent at any time. Write to support@denkarena.com. You may also lodge a complaint with a data protection authority.

12. Children

DenkArena is not directed at children under 13. We do not knowingly collect data from children under 13.