Start2Win 1.3.1

All you need to do is enter the end points of the start line. You do this by navigating to starboard and port marks of the start line and hit the respective button in the app. Then you enable the countdown timer and are ready to race!

Here is part of the the official manual:

1. Functionality
Start2Win is an Android app for smart phones and tablets. It supports the racing sailor to start perfectly.
During the pre-start phase you sail to the start boat and start buoy and take their coordinates by simply tapping the respective button. The start line and the current position are displayed on the Google Map. To complete the setup, the built in count down timer needs to be synchronized with the starting time.
Based on the current position, the speed and bearing, Start2Win calculates when the start line will be crossed. It can now be estimated if the start line will be reached before, at, or after the start signal.
The sailor can now decide how to steer to assure he arrives at the start line at the optimal point in time.
During the pre-start phase skipper and crew are rather busy navigating their boat as well as observing other boats. So there is hardly any time to read displays.
Utilizing the new “Audio Vario 2 Start” logic, Start2Win provides the most important information acoustically. The logic is anticipated from the well known Variometer used in gliding and paragliding.
There it is the valuable information about climbing and descending, here it is the early or late arrival at the start line. The sailor optimizes the start tactics based on estimation and announcement. Of course proper seemanship must not be jeopardized when using this application.
We wish a great start to win the race!

2. Prior to your first race with Start2Win
It will be helpful to adjust some settings prior to the first use of Start2Win in a race and get familiar with the app.

Boat Settings
Entering a reasonable value for the maximum boat speed prevents false calculations of the arrival time at the start line in case the GPS module provides a wrong value. This happens rarely, but it can happen.
The GPS module supplies rather inaccurate values when moving rather slow. This will also affect calculation and may lead to false estimations. Normally there is no need to select a larger value than the default, entering smaller values needs to be handled with care.

Units
Enter your preferred values here.

Audio Vario and Count Down
You can mute both acoustic outputs here.
Don’t forget to un-mute prior to the race so that you don’t need to read the display permanently.

3. Fixing the start line
We are on the water, the race committee has set the start line. First off, Start2Win needs to know the start line, otherwise it is rather useless.
Tap Startline in the Map View. Navigate to the starboard edge and tap Stb Buoy; do the same for the port end of the start line and tap Port Buoy.
Tip: For the first few times you may want to set the points a little inside and towards the pre-start area. This adds some safety buffer to avoid early starts.
Should the race management decide to modify the start line, one of the two, or even both end point positions of the start line can always be re-entered as described above.
Should you have mixed up Stb. and Port buoy positions, or the race is started from the other side of the start line, you can always tap Switch Buoys.

4. Synchronizing the start time
Tap Timer in Map View. Use the slider to adjust the minutes to the start. Tap Set to synchronize with the respective signal of the race management.
Re-set the timer if it was not accurate enough at a later race committee signal.