Three ways to start
A mass start gives everyone the same start time — one press for the whole field. An interval start sends someone off every few seconds, anywhere between five seconds and an hour apart. Or start each entrant individually when things are less orderly.
Every start runs a countdown with sound, so nobody has to shout.
When the signal drops
On a sports field a phone has one bar or none. A tap is not lost either way: the device remembers the time and sends it on once there is signal again — with the time it was actually tapped, not the time the message arrived. The two devices align their clocks beforehand.
Watching along
Parents and spectators open the same address and follow the results without installing anything. At the end you get a list ranked per group and overall, and a CSV file to download. That is the evening of typing gone.
Limits, plainly
A race holds up to 400 entrants. It needs two devices with a browser — start and finish cannot share one. And it is not chip timing: a human presses the button, so the accuracy is that of an attentive person with a thumb ready.
Races are deleted automatically after 60 days, names included. Download the CSV if you want to keep the results.