A .NET 7 Windows Forms interval timer for round-based training, like a boxing round timer. You set the work time, the rest time and the number of rounds.
A small timer engine raises events on every tick, at half-time, in the last ten seconds, at the start of rest, on the next round, on the last round and at the finish. The interface plays a sound for each: a gong, beeps, a count of short beeps for the number of the round, and chimes at the end. All the sounds are synthesized by a small script in the repository, so the project is free to share under the GPL.
The app also starts an embedded HTTP server on port 8080. It serves a small web page and has JSON start and stop endpoints, so the timer can be controlled from a phone’s browser while you are on the mat. There is also an early experiment with a cross-platform .NET MAUI version.