Privacy policy

Last updated: 7 November 2026

Bematist is a running app that measures your cadence and plays music from your own device that matches it.

The short version

Bematist collects nothing, sends nothing, and has no servers.

There is no account, no sign-in, no analytics, no crash reporting, no advertising, and no third-party trackers. The published app does not request network permission and makes no network requests of any kind. Everything it knows stays on your phone. If you’ve turned on backup, your phone may copy this data to your cloud storage, but neither the app nor the developer can access that copy.

What the app stores, and where

All of it is in the app’s own private storage on your device:

What	Why
Your music files’ titles, artists, and measured tempo	To pick a track that matches your cadence
Which folders you chose	So it can find your music again
Cadence readings and track changes from your runs	To show you a run summary and improve matching
Your settings	To remember your preferences

This data is visible only to Bematist. It is removed from your phone when you uninstall the app, and you can clear it at any time from within the app.

Your music files

Your audio files are never copied or uploaded. The app reads them to measure tempo and to play them. Only triage mode, which you start yourself, changes anything in your folders:

Building playlists (the default): Keep and Like add the track to a .m3u8 playlist file in your music folder. The audio files are not changed. These playlist files stay in your folder if you uninstall the app.
Pruning a folder (only if you turn it on): Skip permanently deletes the audio file, and Like adds the track to a .m3u8 playlist file. The app warns you before you start.

Android backup

From version 1.2, if backup is turned on for your phone, Android includes the data listed above in its backup and when you transfer to a new phone. This lets you keep your tempo analysis, run history and settings after a reinstall or on a new phone. Your audio files are not included.

Your backup service handles this copy, not Bematist. The developer has no access to it, and it may remain after you uninstall the app. You can turn backup off in your phone’s settings.

Permissions, and why each one is needed

Permission	Why
Physical activity (`ACTIVITY_RECOGNITION`)	Reads your phone’s motion sensors to count steps and calculate your running cadence. Bematist never sends this anywhere.
Notifications	Shows the run notification with playback controls while the app is in the background.
Foreground service	Keeps measuring your cadence and playing music while the screen is off or you are in another app.
Wake lock	Lets tempo analysis of your library finish with the screen off.

Access to your music uses Android’s document picker, so you choose exactly which folders the app may read. It has no blanket storage permission and can see nothing you did not pick.

Bematist does not request internet permission. It cannot make network requests.

This website

This website uses no cookies, analytics or scripts, and loads nothing from other sites. It is hosted by Cloudflare, which handles ordinary request data such as IP addresses, and may receive reports of connection errors, in order to serve and protect the site. See Cloudflare’s privacy policy.

Children

Bematist collects no data from anyone, including children under 13.

Changes to this policy

Any change will be published here with an updated date. Because the app collects nothing, no change can retroactively affect data already gathered — there is none.

Source code

Bematist is free software, licensed under the GNU General Public License v3. You can read every line of it, including everything described above, and verify these claims yourself.

Contact

Questions about this policy? Send an email.

A note on the other build

This policy covers Bematist, the app published on F-Droid and on the project’s GitLab releases page.

The source repository also contains a personal build used only by the developer, which connects to Spotify, Last.fm and ReccoBeats. That build is never distributed — it cannot be, since Spotify’s Developer Program caps a published app at five users. If you install Bematist from either of those places, you have the local-files-only build this policy describes.