It has all the same core fitness and sports tracking as the Series 3, including built-in GPS and a swimproof design. You can also expect improvements in run tracking and new supported activities like yoga and hiking. It comes packing LTE once again so you can take it out sans iPhone and still make/receive calls, get texts and all other notifications you would on your phone. A new speaker should also make Siri chats and phone calls sound louder and clearer.
The Fitbit Ionic works fine as a Fitbit tracker, but despite being more expensive than our picks or the Apple Watch Series 1, it lacks many smartwatch functions you’d hope to have. It passes notifications from your phone to the watch, but you can only respond to some of them (with only five quick reply lines); and dismissing them (either one by one or as a group) involves annoyingly hard presses and long scrolls. Syncing music files and offline Pandora playlists requires you to use a desktop app, which is laborious. Two Wirecutter writers who tested the Ionic also had trouble setting it up to work with their Android phones (a 2015 Moto X Pure and a 2016 Samsung Galaxy S7) and had to perform significant troubleshooting to get their data to sync. The Ionic’s battery life, even while using GPS for outdoor exercise tracking, is its most impressive feature, lasting at least five days in one test and nearly seven days in another. The Ionic is most useful to Fitbit enthusiasts who want to track outdoor exercise without bringing a phone; it’s not a good option if you’re looking to deal with incoming information.
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.