Which limits your current choice of handset and is going to have a big weight in which watches you can pick from (or vice versa).
The Apple Watch mostly works in a great compatibility with (surprise, surprise) iPhones, as you might imagine.
But that doesn’t mean that iOS users are limited only to the Cupertino’s offering. Android Wear based watches are now finally able to work with iPhone, as well as Pebble and a range of other companies.
Samsung smartwatches are powered by the company’s own Tizen OS:
most of its older devices (like the Gear 2 Neo) only work with a limited number of Samsung phones, although the new Gear S2 is compatible with a much longer list of recent Android developed handsets.Android Wear watches, which is surely surmising from their name – have for a long time only been built to work with Android phones An additional restriction was that the phone should have run an Android OS version 4.3 or newer… Google has added iPhone compatibility to the OS, which should mean most future Android Wear devices are iOS-friendly as well, but not vice-versa.
As with smartphones, Google works on the software – which is based on Google services such as Google Now. But right after the job is done, they will leave you to a will and diligence of the manufacturer, like Motorola, LG, Sony, Samsung and HTC to build the watches.