The company claims that the SpO2 monitor will help its devices look for signs of sleep apnea and other breathing problems, potentially great features for devices that are meant to be worn 24/7. It'll be used primarily in Fitbit's forthcoming Sleep Score Beta, which further analyzes sleep quality using heart rate and breathing data. Starting sometime this November, users with devices that only have heart rate monitors can get a "sleep score" after each night's sleep. Those with an Ionic, Versa, or Charge 3 will presumably have better data thanks to the SpO2 monitor collecting breathing data.
Garmin has been putting out go-to smartwatches for sports lovers for a while now. Running, cycling, swimming, golf - Garmin has had us well and truly covered. Despite the Forerunner name, the 645 Music is more in the mould of the Vivoactive 3 Music. It's got a similar look and also brings the music this time. This helps make the Garmin more of a smartwatch rival to the Apple Watch, Samsung Gear or Fitbit Ionic than before.
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.