What are the ready-made solutions for a smart bracelet (watch)?

Question

Do it yourself

Good day dear friends.
I decided to ask for help, because I don’t have close experience with a smart watch or a bracelet. I would like to buy a smart thing (watch or bracelet) for my development. The next task is needed so that this smart thing has an sdk or api not only for android and ios, but also for linux or windows. I apologize if I didn't phrase my idea well. Thanks in advance.
Naturally, a big request to answer first of all to people who have encountered this problem or worked.

Answer 1

if search is difficult for you, is it worth taking on api or sdk
https://yandex.ru/search/?text=yyfke%20tsfesr%20fzsh...

Answer 2

Pebble

Answer 3

Personally, I don't like smartwatches! I prefer the classics, I order a men's wristwatch for my husband , they fit everything with their appearance. I think every man should have a couple of these.