Bottom line: Some fitness trackers work equally well with an iPhone or Android device, but some smartwatches are built to pair with Android phones so you won’t enjoy full functionality and pairing on an iPhone. The Apple Watch only pairs with the iPhone so is off limits to Android users. Your existing phone choice will play an important part in choosing a smartwatch. You can check your smartphone’s compatibility with a range of Google Wear-powered smartwatches at g.co/WearCheck
Apple is back with the Apple Watch Series 4, the latest in the smartwatch game that's focused on helping wearers live a healthier lifestyle. Running on Apple’s S4 64-bit dual-core processor and the new WatchOS 5 operating system, it’s twice as fast as its predecessor. Available in two sizes — 40 mm and 44mm — it has a 30 percent larger display than the Series 3 and comes in six different aluminum and stainless steel finishes. New improvements include Walkie Talkie mode and a speaker that is 50% louder than in the Series 3. The microphone has been moved to the watch’s opposite side to reduce noise and create clearer phone calls. The bottom, now made from black ceramic and sapphire crystal for better radio wave transmission, is intended to help with cellular reception and call quality.
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.