StartLine is a stand alone GPS based app that runs on Android phones and tablets. As readers of L-36.com know, I tried several apps and GPS assisted technique for starts and they all had serious issues. It was the lack of an viable alternative that led to the development of StartLine. It was developed on the race course over the season and we kept changing it until it actually got us to the line on time in real race conditions. It has large high contrast readouts so you can see it in daylight conditions on a phone. It is on the Google Play store -- search StartLine (one word). There is a flexible waypoint capability included. The screen shows direction and time to the mark as well as speed and heading so that it is our complete race computer. But it is the starting part that was the main driver for the app. The display shows time to the start, time to the line, time to burn, and time to a selected layline. The thing that makes this app work is that you calibrate your speed to the line in the pre-start and that speed and direction are the basis of the time to the line conversion from distance. Thus, you can be heading away from the line and the app will still read how long it will take you, traveling that speed, to get back to the line. The time to the layline allows you to set up well in advance of the start as it is better to burn time early than kill your speed right at the line. As an example, assume you are heading away from the line, when the time to burn is equal to the time you know it takes to turn and accelerate, you tack back and will be at the line at the gun. A lot or work went into the accuracy of the GPS position calculation including interpolation between GPS readings and velocity compensation of position. I have complete instructions at http://L-36.com
under the Android SatrtLine tab.
I hope you enjoy it,