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.
Wirecutter writers have been researching, testing, and writing about smartwatches since early 2013, just after the first Pebble watches were shipped to Kickstarter backers. I’ve personally worn nearly every notable smartwatch since that first Pebble and have written about them for a number of publications, including IT World and Fast Company. I also have extensive experience with Android phones, having written the (since outdated) Complete Android Guide and numerous articles about Android. I also contribute to and help edit the Wirecutter guide to the best smartwatch for iPhones.
Waterproof to 165 feet and tested to military standards for durability, it includes features like a digital compass, altimeter, and barometer that you won’t find in most other smartwatches, as well as more standard tools such as GPS. The WSD-F20 can also function as a flashlight — handy in an emergency — and lets you download maps for offline navigation when you’re far from the nearest cell signal.
There's now a heart rate monitor, as the name suggests, for tracking beats throughout the day and during exercise, a GPS monitor to keep up with your workouts and an NFC chip to enable Google Pay. Add to that the ability to take this underwater up to 50 metres, all on the top of the refreshed Wear OS, and it all rounds out as a very complete smartwatch experience.
The top smartwatches that debuted at the 2017 Consumer Electronics Show included the Casio WSD-F20, Misfit Wearables Vapor and the Garmin Fenix 5 series. Apple released on September 22, 2017 their Apple Watch Series 3 model which offers built in LTE cellular connectivity allowing phone calls, messaging and data without relying on a nearby smartphone connection. 
How frustrating. I really -like- the idea of a smart watch... but it's so hard to find the right one. I'm not an exercise freak so heartrate monitors etc are useless to me. I really like the design of the Samsung watches with their bezels to control it, but the Tizen OS with it's limited apps puts me right off. The Access Grayson watch is beautiful, but the lack of NFC is a deal breaker for me - Google Pay with the convenience of a watch is part of the reason I'd buy one. I don't need to be able to put a sim in it... that's what my phone's for, but GOS would be nice for when I travel, and as a motorbike rider some level of waterproofing is a must. Guess I'm waiting for the next round of watches to see what's on offer.
While you're not getting Spotify or Apple Music here, you are getting enough storage for 500 songs with a process that's fairly easy. You just boot up Garmin Express, select the Music tab and choose which of your own music you want to port over. If you do want to sync over playlists from a streaming service, your only options are iHeartRadio and Deezer.
Why we like it: Compared with a smartwatch or fitness tracker, a dedicated GPS running watch is focused on one category of exercise: outdoor movement. GPS watches offer the fastest GPS signal lock-on and more-precise maps, while also showing up to the second details on your pace, heart rate, mile split times, and a host of other stats on an always-on display. The physical buttons on a GPS watch are easier to use while moving (and without looking), rather than having to swipe or tap on a tiny glass screen. A GPS watch’s longer battery life can better handle endurance events than a smartwatch. And the software and apps behind a good GPS watch provide more statistics and training programs to improve your efficiency. While GPS watches can show notifications, the weather, and a few other smartwatch-like conveniences, they’re much more limited in what can be done from a wrist than a smartwatch—or even a fitness tracker like the Vívosmart.
Fossil’s Q Explorist and its smaller-wrist counterpart the Q Venture are well-made, responsive, fashionable Wear OS smartwatches that offer a lot of color and band options, making them the best option around. They ably run Wear OS (more on the pros and cons of Wear OS itself in a bit) and convey your phone’s notifications to your wrist. Their buttons engage with clean clicks, the Explorist’s center crown moves through lists and notifications much more effectively than swiping, and both screens are responsive and clear.
We pulled together a list of currently available smart watches that met these criteria from Apple, Android Wear, and Samsung. Our list included watches from tech brands like Apple, Asus, and Samsung, as well as fashion labels like Fossil, Nixon, and Tag Heuer. Then, we cross-checked with respected review sites, such as Tech Radar and PCMag, as well as tech retailer Best Buy, to make sure we weren’t leaving out any hidden gems.