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.
It plays a sound for each stage of a round: a gong, beeps, a count of short beeps for the round number, and chimes at the end. A small script in the repository synthesizes all the sounds, 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 I can control the timer from a phone’s browser while I am on the mat. There is also an early experiment with a cross-platform .NET MAUI version.