SprintLine - GPS Lap Timer

SprintLine is a GPS lap timer for riders. Draw a start line and a finish line on the map, then ride — the precise lap time between the two lines is recorded automatically. Circuit, canyon road, or your favorite practice section: all you need is your phone. No account. No server. No sign-up. Every lap and every course is stored on your device only, and no personal data is ever collected or transmitted. Free, ad-free, and it works the same anywhere in the world. ■ How it works Create a course — tap the map to draw a start line (A) and a finish line (B). Start — hit start and wait to cross the line. Ride — the timer starts and stops the moment you cross, and the lap is saved automatically. ■ Three course modes · Round trip — records both directions, A→B and B→A · One way — records a single direction, A to B · Track — continuous laps around a closed loop using one line, with an optional target lap count Add checkpoints to see split times for each section. ■ Precision timing GPS normally updates your position only once per second. SprintLine uses the instantaneous (Doppler) speed at each point to interpolate the exact moment you cross the line. That removes the crossing-time error that builds up under acceleration and braking, using the same principle as professional lap timers. ■ Lean angle gauge Shows your bike's left and right lean in real time and records the maximum lean angle. Mount-orientation calibration means it works with any mount. ■ Analysis and 3D replay · Ride trace visualized on the map as a speed heatmap · Top speed, average speed, total distance and other ride stats · 3D flyover replay with a chase cam that follows your line · Calendar view to see your records by date ■ Your data is yours · Laps and courses are stored locally on your device (no central server database) · Export and import courses as JSON files — share courses with friends, no server needed · Automatic backup to your Downloads folder, so your records survive a reinstall ■ Anywhere, for anyone · 10 languages (한국어, English, 日本語, 中文, Español, Français, Deutsch, Português, Italiano, Русский), switchable inside the app · Metric (km/h, m) and imperial (mph, ft, mi) units · Worldwide maps (OpenStreetMap), not limited to any one country — no setup required ■ Permissions · Location — required for ride measurement. Background location is used so timing continues even with the screen off. · Location data is used only on your device, for lap calculation and trace storage. It is never transmitted. Draw a line on the map and ride. SprintLine handles the timing.