Looks very interesting to me. There are a couple of features that are especially important to me.

- Good accuracy sleep tracking

- GPS ( I know this uses up a lot of battery but could be off by default)

- Self-hostable servers. (I'm a very privacy conscious person, and also I don't want to be bound to an ecosystem that might disappear one day)

I'm gonna keep an eye on this project. It really looks very interesting. I hope it gets far.