I Am Sail app for iPhone and iPad
The perfect app for dinghy racing. Race timer with the usual countdown modes but this one also records your route so that you can see where you have been on the map. See where you went wide or off course and lost those precious seconds. The timer also includes a speed readout to help you fine tune your rig.
There is also a handy handicap calculator that tells you how far ahead (or behind) of your rival you need to be in order to beat them based on PY.
History of races and stats are stored so that you can look back to see how your performance has changed.