Speedometer and odometer seem accurate, and I've pretty much stopped using my trusty old Cateye. Once in a while, the speedometer seems to get behind, perhaps because of a momentary lapse in GPS connections or some other latency issue, but generally it's fine. I've tried several other apps but none of them quite do the job as well as Bike Computer. The display is clear and easy to read. UPDATE: I've removed a star, because it lacks KM/miles label! Was in KM mode without realizing it!!! Pls fix.