Samsung can't make up its mind whether it wants to use Google's Android Wear or built its OS. The company recently switched its smartwatches from Android to Tizen, but that was before Google announced Android Wear. (Samsung Live is the only Samsung watch that is still powered by Android Wear, but it's not a watch that I would recommend to anyone.)
The Samsung Gear S is powered by Linux-based Tizen. One of the greatest features of Samsung Gear S is the built in cellular capabilities. The watch supports both GSM and CDMA technologies so you can use SIM from T-Mobile, AT&T and other GSM players or get one from Verizon.
This Linux powered smartwatch has built-in GPS and was capable or making phone calls even before the Apple Watch could do that. But unlike the Apple Watch, it gets its own phone number for making calls. And it still needs a Samsung (not just any other Android handset) phone for many apps and notifications.
Display: 2.0” Curved Super AMOLED (360 x 480)
Processor: Dual core 1.0 GHz
Dimensions: 2.28in x 1.57in x 0.49in
Weight: 67 g
Connectivity: WiFi :802.11 b/g/n, A-GPS/Glonass, Bluetooth, USB 2.0
Sensors: Accelerometer, Barometer, Gyro Sensor, Geomagnetic Sensor, HR Sensor, Light Sensor
Pros: Built in cellular network and GPS; no need for phone to place calls
Cons: Locked into Samsung ecosystem
Limited apps and content
The watch is available with carriers under contract and without contract.