Privacy Policy
Chess Puzzles application.
Effective date: 10 October 2026.
This document is the privacy policy of the Chess Puzzles application for Android and iOS. It explains what data the application processes, why, and with whom it is shared.
How to delete your data
Option 1. In the app
- Open the Chess Puzzles application and open any puzzle.
- Tap the trophy icon in the top right corner to open the leaderboard.
- Tap “Profile”.
- Tap “Reset progress” and confirm by tapping again.
Your score and the history of solved and failed puzzles are deleted both on the device and on our server.
Option 2. By request
Write to
What is deleted: nickname, profile icon, game identifier, score, streak, and the lists of solved and failed puzzles.
What is retained: nothing. After deletion no player data remains with us.
Retention periods: data is kept while you use the application. After a deletion request it is erased within 30 days. Server technical logs, which contain no nicknames or results, are kept for no longer than 90 days.
1. Who processes the data
The application is developed by Electronic Hand Ltd.
For privacy questions and data deletion requests, write to
2. No account required
The application does not ask for an email address, phone number, real name or date of birth, and does not use third-party sign-in. You can play right after installing.
3. What data is processed
| Data | Source | Purpose |
|---|---|---|
| Game identifier | Generated by the application itself on first launch as a random string. It is not linked to your device, Google or Apple account, or advertising identifier. | Distinguishing players on the leaderboard |
| Nickname and profile icon | Chosen by the player. A real name is not required. | Display on the leaderboard |
| Game statistics: score, solved and failed puzzles, streak | Produced during play | Scoring and leaderboard |
| Push notification token | Issued by Firebase Cloud Messaging (Google) for this installation of the application. On iOS it is based on the Apple Push Notification service token. | Delivering push notifications (announcements), only if you allow notifications |
| Purchase status | The “Remove ads” purchase is processed by the store (App Store, Google Play or RuStore). The application only learns whether the purchase was made. | Turning off interstitial and app-open ads; restoring the purchase |
| Settings: language, sound, vibration | Chosen by the player | Stored on the device only, never transmitted |
The application does not request access to location, camera, microphone, contacts, files, or the list of installed applications. It only asks for permission to send notifications and, on iOS, for permission to track (see “Advertising”).
4. Advertising
The application is free and shows ads through Yandex Mobile Ads. The advertising service acts as an independent data controller and may collect technical device information, including the advertising identifier, IP address, device model and operating system version. Through its mediation, ads may also come from partner networks, such as Liftoff (Vungle) and Unity Ads, which may collect the same kind of data.
We do not share your nickname, game identifier or results with the advertising service.
On Android, you can limit ad personalisation and reset your advertising identifier in Settings → Google → Ads.
On iOS, the advertising identifier (IDFA) is available to the advertising service only if you allow it in the “Allow tracking” dialog that the application shows once, before the first ad. You can change your choice at any time in Settings → Privacy & Security → Tracking.
If you buy “Remove ads”, interstitial and app-open ads are no longer shown. Optional rewarded ads stay available.
5. Push notifications
The application uses Firebase Cloud Messaging by Google to send occasional announcements. The application asks for permission first; if you decline, no notifications are shown.
To deliver notifications, Firebase stores a notification token for your installation and the topics it is subscribed to: all players and the language of the game. Firebase does not receive your nickname, game identifier or results. Firebase Analytics is not used.
You can turn notifications off at any time in your device settings.
6. In-app purchases
The application offers one optional purchase, “Remove ads”. Payment is handled entirely by the store you installed the application from: the App Store, Google Play or RuStore, under that store’s own terms and privacy policy. We do not receive your payment details or account information.
The purchase status is kept on your device and can be restored through the store with the “Restore purchases” button on iOS, or automatically on Android.
7. Who receives the data
- Our server — game identifier, nickname, icon and game results. Transferred over HTTPS; requests are signed.
- The advertising service — technical device data as described above.
- Firebase Cloud Messaging (Google) — the notification token and topic subscriptions, as described in section 5.
- The store (App Store, Google Play or RuStore) — the details of a purchase, as described in section 6.
We do not sell data and do not share it with third parties for marketing.
8. How long data is kept
Results are kept while the application is installed and while the record remains on the leaderboard. See the deletion instructions at the top of this page.
Uninstalling the application erases all data on the device, but does not remove the server record.
The notification token is deleted by Firebase after the application is uninstalled or stays unused for a long time.
9. Children
The application is not directed to children under 13 and does not knowingly collect data from children. If you believe a child has provided us with data, contact us and we will delete it.
10. Security
All communication with the server uses HTTPS. Requests are signed so that results cannot be forged. Access to the database is restricted to the developer.
No method of transmission over the internet is completely secure, so absolute protection cannot be guaranteed.
11. Changes to this policy
We may update this document. Any new version will be published at this same address with a new effective date.