I like my Xiaomi RealMi Watch 2 Pro, or something like that. Was 3-4k baht I think. Good for tracking exercise. The GPS is more accurate for distances ran/cycled than Strava on the phone.
Gives a big break down of your night's sleep (the different stages etc) if I wear it at night, which I don't.
I have no problem with Beijing or anyone else having all my personal data.