F3K Timer

In F3K competitions, timekeepers are short of time to start, stop, restart and write flight times between launches. Most of them use two stopwatches, so they get short of hands. F3K has the following features:
Start and stop of main chronometer with on-screen button or volume button
Automatic zero reset
Keeps track of previous times
Secondary Working time stopwatch (10, 15, 6 or 7min) selectable by longpressing st chronometer)
If not yet running, Working Time stopwatch starts when main chronometer is first started
Main chronometer stops when working time finished
30 seconds landing time