Inside the Charge 3 are an accelerometer, gyroscope, optical heart rate monitor, and an SpO2 sensor for tracking blood oxygen levels. The Charge 3 is the third Fitbit device to include an SpO2 sensor, following in the footsteps of both the Fitbit Ionic and the Versa smartwatches. However, currently the SpO2 monitor lies dormant inside all of these devices as Fitbit hasn't made use of it yet.
The watch faces themselves are classic Kate Spade designs. You get a sultry winking moon face with perfectly curled lashes, calling you a leading lady; cute bubbly balloons for a digital watch face with numbers; a speeding cab that reassures you that you'll be there in a New York minute; and a daisy that loses petals as the time ticks away in a classic game of "He loves me; he loves me not."
Samsung's Galaxy Watch, a Tizen OS watch (starting at $329), is our favorite smartwatch for Android users. In addition to up to four days of battery life and a great design, the Galaxy Watch offers built-in GPS, heart rate sensor, water-resistance, Samsung Pay support, plus a nifty rotating bezel for navigating the interface. You can also download music from Spotify to the watch for offline listening. However, you get far fewer apps than you would with a Wear OS watch.