Unparalleled functionality. Confusing interface.

There is nothing else quite as awesome as this app. GPS+video+OBD-II data+custom tracks=amazing road or track videos and detailed data for number geeks. But the interface is arcane, confusing and not entirely consistent with iPhone conventions, so it has a steep learning curve. Plan to spend some time figuring it out. But once you do, youll be tracking your track days, autocross, and perhaps even your daily commute, and making video of your best laps with data overlays and picture-in-picture of your reference laps or 2nd camera. Fun stuff, worth the work!

Robert Mohns about Harry's LapTimer Grand Prix, v17.0.6