Yes, as far as I know, it is only limited to iphone and apple watch.
If you are somehow able to get the watch activated, it does support 4G for calls and internet.
It is the unlocked LTE version, but uses e-sim. It cannot be activated in India as no Indian carrier supports e-sim for non apple devices.
There are no issues with it other than the slight wear on the band, which can be seen in the pictures.