They include a heart rate monitor, pedometer and altimeter to track steps taken and stairs climbed and often a GPS chip to record your distance covered. They will sync with your smartphone to give you a suite of tools to monitor your exercise progress. Many of them will offer notifications of incoming phone calls, text and email alerts as well. But they are designed with fitness tracking in mind. If you are happy using your smartphone for your day to day messaging, calendar, apps and music, a fitness tracker will suffice.
The Passport is versatile in that it works with Android and iOS mobile devices. And it features the ability to make phone calls with its built-in microphone and speaker. You can use voice commands (the Passport leverages your phone's voice recognition system; such as Apple's Siri for iOS devices or Google Now for Android) to control the mobile device from the watch. And because of the analog watch face, you can easily see the time in bright sunlight.
Our top pick for most people is the Apple Watch Series 4 with GPS (starting at $399), which has a huge display, ultra-fast processor, Raise to Speak Siri, fall detection and a built-in electrical heart rate sensor for taking on-the-go electrocardiograms. It also runs watchOS 5, which makes the watch even more useful with automatic workout-tracking, offline podcast playback and a Walkie-Talkie voice chat feature.