KevLines

Real-time exercise form analysis on your device. No internet required. See your skeleton, joint angles, and rep count as you lift.

KevLines is an on-device exercise form analysis app for iPhone. Point your camera at yourself while you train, or import a saved video, and the app overlays a live skeleton with joint angle measurements, rep counts, and tempo feedback — all processed entirely on your device with no internet connection required.

What it does

Live camera mode: see your skeleton overlay in real time as you lift, and export the annotated video when you're done Saved video mode: import any video from your library and get a processed, annotated export in seconds Tracks joint angles using true 3D world coordinates so readings don't shift with camera position Counts reps and classifies tempo phases (eccentric, pause, concentric) automatically Supported exercises: Squat, Barbell Row, Lat Pulldown, Bicep/Tricep Elbow, and Shoulder Assessment (postural, bilateral) Private by design Everything runs on your iPhone using MediaPipe and Apple's hardware video pipeline. No video is ever uploaded anywhere.

Beta notice This is an early beta. Expect rough edges — UI is unfinished, workout history is not yet persisted, and some features listed in the roadmap are still in progress. Feedback on accuracy, performance, and crashes is especially helpful.