Busy Status Bar

If you're looking for something with an addressable LED matrix in a clock style form factor, the Ulanzi TC001 [0] for ~$50 is worth having a look at.

Doesn't quite have the same aesthetic but inside it's just an ESP32 (flashed via the USB-C port) and there's various mature open source firmware replacements. I use awtrix[1] on mine and it's very easy to tie in HomeAssistant for doorbell notifications and that sort of thing. I did also knock up a Pomodoro app for it.

0: https://www.ulanzi.com/products/ulanzi-pixel-smart-clock-288...

1: https://github.com/Blueforcer/awtrix3

I was going to say that $200 seemed awfully expensive for a programmable kitchen timer.

I've had a project idea for a while that would require a bit more juice. In short, I want to make a music practice timer for ADHD kids that avoid actually playing music during practice time. I want it to be beefy enough to run some simple ML for detecting instruments being played, and I only want the timer to count down while the instruments are playing. I picture it looking a lot like the clock above, but with something like a Raspberry Pi jammed inside so it's got enough power to reliably detect "violin."

Any ideas on hardware for that?

Hate to burst your bubble, but as an amateur musician I fear this would backfire, or at least fail to result in any improvement in playing ability. Silence and time are absolutely critical to playing music. By analogy, measuring 'time spent drawing bow across strings' would be as useful to a violin student as 'time spent pressing foot on accelerator' would be to a driving student!

From my own experience learning to play the organ, I have improved least when I play relatively fluidly, practising with music well within my abilities. On the contrary, the most improvement has come when I've slowed down, allowed myself to count the timing, repeat sections, read the sheet music more carefully or even just take a break entirely. So although silence won't improve one's playing by itself, I think it's a natural by-product of an effective studying technique that, if at all possible, shouldn't be discouraged with such a timer.