Suggest a smart watch for which you can write applications yourself?

Question

Android

What I know at the moment:
1. There is Apple, it seems like you can develop applications for them yourself, but they cost a lot, and it’s desirable to be in the Apple ecosystem (
2. Pabble, as far as I understand, at the moment they were bought out and "ripanuli" , although the option was good in my opinion :( As I understand it, there are no underground productions or analogues of these watches?
:( Are there universal applications or do they write their applications for different hours?

Answer 1

Garmin, Fitbit