Privacy Policy for ProtonChess

At ProtonChess, we respect your privacy. This Privacy Policy explains what information we collect, how we use it, and your rights regarding your data when you use our mobile app (“ProtonChess”).

By using ProtonChess, you agree to the collection and use of information in accordance with this policy.

1. Information We Collect

1.1 Information You Provide Voluntarily

• Email Address – We may collect your email address only if you choose to provide it (e.g., when sending feedback, requesting technical support, or contacting us for any reason). Email is never required for normal app usage.
• Username – When you create a profile (optional), we may store a username of your choice. This username is displayed only within the app (e.g., on your profile screen). You are not required to use your real name.
• No Personal Identifiers – Account creation does not require your real name, address, phone number, or any government‑issued ID.

1.2 Information Collected Automatically

• Performance Data – To personalise your learning, we record: your move‑by‑move accuracy in openings and puzzles, time spent on each position, review history (dates, success/failure rates), and stability/difficulty scores generated by the algorithm.
• Game Data – When you import or play games, we store the PGN (Portable Game Notation) and any analysis you perform.
• Usage Statistics – We may collect anonymous usage data (e.g., which features you use most often, crash logs) to improve the app.

1.3 No Financial Information

We do not collect, store, or process any financial information (credit card numbers, bank account details, etc.). If you purchase a subscription, all payments are handled exclusively by the App Store, and we never receive your full payment details.

2. How We Use Your Information

• To provide and maintain the app – training data powers your progress tracking and badge system.
• To improve user experience – Usage statistics help us fix bugs and optimise features.
• To respond to your inquiries – If you contact us via email, we use your email address only to reply.
• To display your chosen username – Within the app’s profile section (no other use).

3. Data Sharing and Third‑Party Services

3.1 Lichess API

ProtonChess uses the official Lichess API to fetch puzzles and game data. When you request a puzzle, your IP address and puzzle rating band are sent to Lichess servers. This data is used solely to retrieve puzzle content and is governed by the Lichess Privacy Policy. We do not store or share any data received from Lichess beyond what is necessary for the app’s functionality.

3.2 App Store (Subscriptions)

If you purchase a subscription, the transaction is processed by the App Store. We only receive confirmation of your subscription status (active/expired) and the expiry date. We do not receive your credit card information.

3.3 No Other Third‑Party Sharing

We do not sell, rent, or trade your personal information to any third parties. We do not use third‑party analytics or advertising SDKs that would collect personal data.

4. Data Storage and Retention

• Local Storage (Hive) – Most of your data (cards, progress, game history) is stored locally on your device using Hive. This data never leaves your device unless you explicitly export it.
• No Cloud Backup – We do not maintain any cloud servers that store your personal data. Your progress is tied to your device. (If you wish to transfer data, you can manually export/import.)
• Retention – Data remains on your device until you uninstall the app or manually delete it. If you contact us via email, we retain your email and correspondence only as long as needed to resolve your issue (typically 90 days).

5. Your Rights

Depending on your location (e.g., EU/EEA under GDPR), you may have the right to: access, rectification, erasure, restriction, objection, and data portability.

Because almost all your data is stored locally on your device, you can directly manage it by uninstalling the app or deleting the app’s data from your device settings. For any data we might hold (e.g., email correspondence), please contact us using the information in Section 8.

6. Children’s Privacy

ProtonChess is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child has provided us with personal information, please contact us. We will take steps to delete such information.

7. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. Any changes will be posted on this page, and the “Effective Date” at the top will be revised. We encourage you to review this policy periodically.

8. Contact Us

If you have any questions about this Privacy Policy or wish to exercise your data rights, please contact us at:

Email: support@atomchess.io

9. Legal Basis for Processing (GDPR for EU users)

For users in the European Economic Area, we process your data based on: Legitimate Interest – To provide and improve the app’s core functionality (learning, puzzle solving); and Consent – When you voluntarily provide your email address to contact us. You have the right to withdraw consent at any time by contacting us.