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.
The Apple Watch Series 3 is a really nice smartwatch that does exactly what it should. This is easily one of the best smartwatches on the market. It’ll give you quick access to notifications, allow you to pay with your wrist, give you turn-by-turn directions, and it’s a decent fitness tracker. In terms of design, it doesn’t feel like Apple cut too many corners with the overall look and feel of the device. Even the Sport model (the cheapest one of the bunch) feels like a well-built piece of hardware.
"Sport watch" functionality often includes activity tracker features (also known as "fitness tracker") as seen in GPS watches made for training, diving, and outdoor sports. Functions may include training programs (such as intervals), lap times, speed display, GPS tracking unit, Route tracking, dive computer, heart rate monitor compatibility, Cadence sensor compatibility, and compatibility with sport transitions (as in triathlons). Other watches can cooperate with an app in a smartphone to carry out their functions. They are paired usually by Bluetooth with a smartphone. Some of these only work with a phone that runs the same mobile operating system; others use a unique watch OS, or otherwise are able to work with most smartphones. Paired, the watch may function as a remote to the phone. This allows the watch to display data such as calls, SMS messages, emails, calendar invites, and any data that may be made available by relevant phone apps. Some fitness tracker watches give users reports on the number of kilometers they walked, hours they slept, and so on.
For a device that gives you more of the functionality you enjoy with your smartphone, you’ll want to opt for a dedicated smartwatch. The leading players at the moment are the Apple Watch for iPhone users and the Samsung Gear S3 for those with Android phones. Apple Watch has its own operating system, Samsung employs its Tizen OS, and a host of other smartwatches use the Google Wear operating system.
The Apple Watch Series 4 is now on sale, and it's the best smartwatch you can buy right now. The redesigned device, which starts at $399 for the GPS model and $499 for the cellular version, is the best smartwatch you can buy. It has a larger display and slightly bigger case size while retaining the same rounded square design the watch is known for. Even more importantly, Apple received FDA clearance for a new electrocardiogram feature that can take a 30-second EKG and diagnose atrial fibrillation.