I built this because I wanted to follow 4-7-8 breathing without opening a bloated app.
The screen only shows what to do: inhale for 4 seconds, hold for 7, exhale for 8. It can run once or keep looping.
I used Vanilla JS and no dependencies. With AI, it is easy to keep adding things. Here I tried to hold back. It was just a timer, so I treated it like a timer.