Privacy Policy

Last updated: 19 July 2026

Your games and analysis stay on your phone. All chess analysis (Stockfish, Maia-2) runs entirely on-device; we operate no server that stores your games. We do not send your PGNs, moves, positions, chess usernames, opponent names, engine analysis, or ratings anywhere — this is enforced by an automated contract in the app's code, not just policy.

Data we collect

Limited app usage analytics and crash diagnostics, via Google Firebase (Analytics and Crashlytics). Examples: which screens are used, that a drill was completed, that the app crashed and the technical stack trace of the crash. Event values are categorical labels and bucketed counts — never chess game content.
This data is tied to a randomly generated app identifier. It does not contain your name, email, or chess account. Because that identifier is stable, the data is pseudonymous rather than anonymous.
That identifier comes from an anonymous Firebase account the app creates automatically on first launch. It is not a sign-up, asks nothing of you, and holds no personal details — but it is what links your usage analytics and crash reports to each other over time. There is currently no in-app setting to turn this off.
Google's analytics service derives coarse location (country/region, from IP address), device model, and OS version. The IP address itself is not stored in our analytics exports.

Data stored only on your device

Games you import (PGN, evaluations, drill state), stored locally in the app's sandboxed database.
Player progression (level, XP, achievements, streak), stored in device preferences.
Coach detector telemetry powering the in-app "Coach detector insights" view — local only; clear it any time via that screen's "Clear telemetry" button.

Cloud backup

BlunderZero does not currently offer cloud backup. Your games, drills and progress exist only on your device, and nothing in the app uploads them. If we add backup later, this policy will say exactly where the data goes and what we can see, before the feature ships.

Third-party sources you may connect to

Lichess and Chess.com game archives. Connections happen directly from your device to those services. Your platform username is used on-device to fetch and label your games; it is never attached to our analytics.

Data retention

Usage analytics events are retained for 14 months and then deleted automatically.
Crash diagnostics are retained for 90 days (Firebase Crashlytics' standard retention).
Our analytics warehouse copies expire on the same 14-month schedule.

Data deletion

Uninstalling the app deletes all locally stored data and stops all collection. Already-collected pseudonymous analytics are then deleted automatically at the end of the retention periods above.
You may email us to request earlier deletion. Because the analytics identifier is random and not shown in the app today, we may be unable to isolate your specific installation's records from your description alone; records we cannot isolate still expire on the retention schedule above.

Children

The app is not directed at users under 13.

Changes

If this policy changes, the new version will be linked from the app and the store listing.

Contact

support@socialplayai.com