The live speedometer is TripRank’s front door: real-time speed derived from high-rate GPS and fused with the phone’s motion sensors, so the number stays honest through tunnels, underpasses, and urban canyons where raw GPS drifts or drops. It renders on the phone and on CarPlay, sized like instrumentation rather than an app.
Underneath the display, the same stream is being recorded into the trip trace — which is what separates a speedometer from a logbook. The number you glance at while driving becomes the curve you review after: speed over the whole route, with distance, duration, and altitude attached. Car speedometers legally over-read; this one shows measured ground speed and keeps the receipts.
