Privacy Policy
Last updated: 13 January 2026
mathr ("we", "us", or "the app") is a brain-building game designed to improve your math calculation skills. This Privacy Policy explains what data the app collects, how it is used, and your rights regarding that data.
1. Data We Collect
1.1 Local Data (stored in your browser)
The app stores gameplay progress and preferences locally in your browser using localStorage. This includes:
- Your current level and attempt count
- History of past challenges (questions and answers)
- Cached leaderboard data
This data never leaves your device unless you explicitly choose to sign in and share your score on the leaderboard.
1.2 Optional Bluesky/ATProto Login
You may optionally sign in with your Bluesky (ATProto) account using OAuth. When you do, the app stores your session information (handle, avatar, and authentication tokens) locally in your browser. This allows you to:
- Post your score to Bluesky
- Appear on the public leaderboard
We do not store your Bluesky password. Authentication is handled securely via the ATProto OAuth flow.
1.3 Leaderboard Submissions
When you submit a score to the leaderboard, the following information is sent to our server and stored:
- Your Bluesky identifier (DID) and handle
- Your display name and avatar URL (if available)
- Your score: level reached, total successes, and total challenges attempted
- Timestamp of submission
This data is publicly visible on the leaderboard.
1.4 Analytics
The app uses Ahrefs Analytics to collect anonymised usage data. This helps us understand how the app is used and improve the experience. Ahrefs may collect:
- Page views and navigation patterns
- Device type and browser information
- Approximate geographic location (country/region)
For more information, see the Ahrefs Privacy Policy.
2. How We Use Your Data
- To save and restore your game progress locally
- To display a public leaderboard (if you choose to submit your score)
- To analyse usage patterns and improve the app
3. Data Sharing
We do not sell your personal data. Data may be shared with:
- Bluesky / ATProto network — if you post your score, it becomes a public Bluesky post
- Ahrefs — anonymised analytics data
- Upstash (Redis) — leaderboard entries are stored on Upstash infrastructure
4. Data Retention
- Local data remains in your browser until you clear site data or uninstall the app.
- Leaderboard entries are retained indefinitely unless you request deletion.
5. Your Rights
You can:
- Clear your local data at any time via your browser settings
- Sign out of Bluesky to remove your session from the app
- Request deletion of your leaderboard entry by contacting us
6. Children's Privacy
The app is designed to be family-friendly and does not knowingly collect personal information from children under 13. If you believe a child has provided us with personal data, please contact us so we can delete it.
7. Changes to This Policy
We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated "Last updated" date.
8. Contact
If you have any questions about this Privacy Policy, please contact Pixeline.