The operating system you choose depends solely on the type of smartphone you have because the smart watch is paired with your smartphone. If you own an Android smartphone, your smart watch should have Android Wear or Tizen. If you own an iPhone, choose an Apple Watch. For example, the Samsung Gear S3 runs Tizen and is compatible with both the Android and iPhone.
If you want a smart watch that uses cellular data without using up the battery, consider upgrading to the Samsung Gear S3. A close cousin to the Gear Sport, the S3 has all the perks of an LTE smart device (downloading apps, texting, checking email) and, unlike the Apple Series 3, it won’t quit after three hours. In fact, you could feasibly get 72 hours out of this LTE version of the Samsung Gear Sport.
The Apple Watch boasts cutting-edge smartwatch tech including mobile payments with Apple Pay, stand-alone GPS, full waterproofing up to 50 meters, and thousands of apps. The user interface is very simple and attractive. It's easy to use and it has advanced, easy-to-use fitness tracking features, thanks to a plethora of sensors and an excellent heart rate monitor.
For deeper integration with your Android phone, you can give Google's Wear OS platform a try with Fossil's $275 Q Control touchscreen smartwatch. It lacks GPS and support for NFC payments, which is why the Gear Sport is a better fitness-focused smartwatch for Android users, but Fossil's Google Assistant integration and stylish design make it a solid contender. However, smartwatches with Qualcomm's new Snapdragon Wear 3100 processor start shipping in October, so you may want to hold off until we put them to the test.