Privacy Policy

Mateflow · Effective 28 June 2026 · Last updated 28 June 2026

This Privacy Policy describes how Mateflow (“the App”), developed by sdtareq (“we”, “us”, or “our”), handles information when you use our mobile application on Android or iOS.

Summary: Mateflow is designed to work offline. Chess puzzles ship inside the App; your puzzle attempts, rating, streaks, motif progress, and settings are stored on your device only. We do not operate user accounts and we do not sell your personal data. If you use the free version, Google AdMob may collect data to show ads, as described below.

1. Information stored on your device

The App stores the following data locally on your phone or tablet:

Puzzle attempt history — per-puzzle records (puzzle ID, motif, correctness, solve time, hint usage, timestamp) in a local SQLite database.
Rating & progress — your puzzle rating, calibration status, motif accuracy summaries, and personal bests used for adaptive difficulty and charts.
Streaks — daily training streak, daily puzzle streak, longest streaks, last practice dates, and streak-freeze count.
Onboarding & sessions — whether onboarding and calibration are complete, daily set completion, pro-mode unlock state, and session counters.
App preferences — sound, haptics, dark mode, board coordinates, and colorblind-safe board toggle.
Purchase status — whether you have bought the “Remove Ads” in-app purchase (is_premium flag in local storage).
Ad frequency counters — how many sessions have completed since the last full-screen ad, stored locally so ads are not shown too often.

Puzzle positions and solutions come from a bundled puzzle database (sourced from Lichess under CC0). This content is not personal data. Your progress stays on your device unless you clear app data, use in-app “Reset progress”, or uninstall the App. We do not upload this data to our own servers.

2. Information we do not collect

We do not require you to create an account. The App does not ask for your name, email address, phone number, or precise location for its core features. We do not use Firebase Analytics, Crashlytics, or similar third-party analytics SDKs in the App. Solving puzzles does not require an internet connection.

3. Third-party services

Google AdMob (free version only)

If you have not purchased “Remove Ads”, the App uses Google AdMob to display:

Banner ads on the home screen and session result screen.
Interstitial ads occasionally after a completed puzzle set (not during an active solve).
Rewarded ads only when you choose to watch them — for example, for a hint during a puzzle, to continue Puzzle Rush, or to earn a streak freeze.

AdMob and its partners may collect and use information such as advertising ID, device type, IP address, and ad interaction data to serve and measure ads.

Learn more in Google’s policies: Google Privacy Policy · AdMob & user data

Where required by law, the App may show Google’s User Messaging Platform (UMP) consent form before personalized ads are served. You can also limit ad personalization in your device settings.

In-app purchases

Purchases are processed by Google Play (Android) or the Apple App Store (iOS). We receive only what the store provides to confirm purchase status (e.g. that “Remove Ads” was bought). Payment details are handled entirely by the store, not by us.

Lichess puzzle data

Tactical puzzles included in the App are derived from the Lichess open database (CC0). Using the App does not send your games or solves to Lichess. See lichess.org/about for Lichess’s own policies.

4. How we use information

To provide chess tactics training, adaptive puzzle selection, motif teaching, streaks, theme maps, and progress charts inside the App.
To remember your preferences and onboarding status between sessions.
To honor your “Remove Ads” purchase and stop showing advertisements.
To show ads in the free version (banner, occasional interstitial, and optional rewarded ads).

5. Data retention and deletion

Attempt and progress data accumulates on device until you clear it or uninstall.
You can reset progress from Settings in the App, which clears local streaks, rating history, and database records.
Uninstalling the App removes locally stored data from your device.
You can also clear the App’s storage in your device system settings.

6. Children’s privacy

The App is an educational chess tactics trainer and is not directed at children under 13. We do not knowingly collect personal information from children. If you believe a child has provided us information, please contact us and we will assist with deletion where applicable.

7. Security

Because data remains on your device, its security also depends on your device passcode, biometrics, and operating-system protections. We recommend keeping your device software up to date.

8. International users

The App is available worldwide. Local data stays on your device. Third-party ad and payment providers may process data according to their own policies and legal bases.

9. Your choices

Remove ads — purchase “Remove Ads” in Settings (one-time, non-consumable).
Limit ad tracking — use your device’s advertising / privacy settings.
Reset progress — use “Reset progress” in Settings or clear app storage on your device.
Colorblind-safe board — enable in Settings for higher-contrast square colors and move highlights.

10. Changes to this policy

We may update this Privacy Policy from time to time. The “Last updated” date at the top will change when we do. Continued use of the App after an update means you accept the revised policy.

11. Contact

For privacy questions or requests regarding Mateflow, contact the developer via GitHub: github.com/sdtareq