Where to read about the development of fitness bracelets?

Question

Mobile development

Tell me where you can see the documentation on developing applications for fitness bracelets. Let's say I want to make a fitness application and bind the ability to pair it with a fitness bracelet / watch. Honestly, Google is not responding to the request

development of mobile applications for fitness bracelets

and this is sad ((

Ps or look for the api of each bracelet?

Answer 1

You need an understanding of how BLE (Bluetooth Low Energy) works.
In general, the Gadgetbridge library is best suited for your task, there is support for a large zoo of bracelets.
https://gadgetbridge.org/
https://github.com/Freeyourgadget/Gadgetbridge
PS Never search in Russian for problems related to programming. Only in English!

Answer 2

https://blog.elcomsoft.ru/2019/05/kak-apple-i-goog...
And who said that the manufacturers. bracelets are interested in implementing and supporting a common API for all?
IMHO, without reverse engineering for some models it will not be possible to pull out data at all.