Bematist

Bematist matches the music it plays to your running cadence. It reads your steps per minute from your phone's motion sensors and picks tracks whose tempo fits the pace you're actually running, switching automatically as your pace changes. Half- and double-tempo tracks count as a match too, so a 172 BPM track suits an 86 SPM pace and vice versa.

When the step counter can't be trusted — on a treadmill, or with the phone in a bag — you can set the BPM range by hand during a run instead: drag it round the dial, and pinch to make it wider or narrower.

Every track is analysed for tempo on-device, directly from the audio files in your library, so matching works entirely offline once your library is scanned — no account, no network, no server.

Triage mode lets you rate tracks while you run — skip, keep or like, by an on-screen gesture or an earbud button — and sorts them into playlists afterward. Every run is logged with its cadence and track-matching detail, browsable afterward in session history.

Bematist collects nothing and has no servers. It plays music from files already on your device.

Free and open source, GPLv3 licensed.