Karttracker

KartTracker turns your Fenix into a proper karting lap timer. Drive to the start/finish line, press START to arm it, and go. GPS detects every crossing and times each lap automatically — no beacons, no transponder, no phone on track. While driving you see a big live lap timer, your last 3 laps (green when you beat your best), best lap, and live HR. On finish it uploads the session and shows a QR code on the watch — scan it to open the full session online: lap chart, racing line on the map, HR, top speed. Also saved as a normal Garmin activity.