Why not the software itself? https://github.com/google/pebble

Or the whole stack: https://open-smartwatch.github.io/

You may like Pinetime smartwatch, which is cheap and runs free software.

I would totally support the Pine64 folks as I already did with the PineCil (really good iron btw, and I have also Wellers), but the PineTime price going from $26.99 in the US to €66.25 if bought in the EU is simply an invite to shop from Aliexpress.

Thanks to tariffs, the PineTime is $26 plus $25 shipping+duty now, so you're in good company.

If a few people in the bay area wanted to do a group buy, you can get up to 5 watches for that same $25 shipping fee...

AFAIK you don't have to buy it in their EU shop. You can order it from China.