Privacy Policy

LBM Watcher · Last updated: May 2026

Short version: LBM Watcher collects no data. Everything you enter stays on your device. No server, no account, no analytics, no advertising.

1. What is LBM Watcher

LBM Watcher is a free, local-only Progressive Web App (PWA) for tracking body weight, body fat percentage, and lean body mass over time. It is developed and maintained independently by FeymLuna.

2. Data collection

LBM Watcher collects no personal data of any kind. Specifically:

No name, email address, or account is required or collected.
No weight, body composition, or health data is ever transmitted to any server.
No usage analytics, crash reports, or telemetry are collected.
No cookies are used.
No advertising networks or third-party SDKs are embedded.

3. Local storage

All data you enter (weight measurements, body fat percentages, and app settings) is stored exclusively in your browser's localStorage — a standard browser feature that keeps data on your device only. This data never leaves your device under any circumstances.

You can delete all stored data at any time from within the app (Data → Clear storage) or by clearing your browser/app data through your device settings.

4. External connections

The app makes no automatic connections to external servers. The only external link present in the app is the optional support link:

Buy Me a Coffee (buymeacoffee.com/feymluna) — this page opens only when you explicitly tap the support link at the bottom of the screen. It is entirely voluntary and governed by Buy Me a Coffee's own privacy policy.

The app loads the JetBrains Mono font from Google Fonts on first load (when online). This is a standard Google Fonts request and subject to Google's privacy policy. After the first load, the app works fully offline.

5. Health disclaimer

LBM Watcher is provided for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. The physiological calculations in this app are based on peer-reviewed research (Alpert, 2005; Kouri et al., 1995) but individual physiology varies significantly.

Do not rely solely on this app to make health or dietary decisions. Consult a qualified healthcare professional, registered dietitian, or sports medicine specialist before making significant changes to your diet, training, or caloric intake.

6. Children

This app is intended for users aged 18 and older. We do not knowingly collect any data from children under 13. Since no data is collected from anyone, there is nothing to collect from minors either.

7. Changes to this policy

If this privacy policy changes, the updated version will be published at this URL with a revised "Last updated" date. Since no data is collected, changes are unlikely to affect users materially.

8. Contact

For questions about this privacy policy, reach out by email or open an issue on the project repository:

contact@feymluna.com

github.com/FeymLuna/lbm-watcher/issues

The developer goes by FeymLuna and responds in English and German.