What separates a smartwatch from a dumb watch? Lots of things, but as smartphones have taught us, apps might be the most important.
Most of the watches we like feature full-fledged app stores, bringing everything from Uber and Yelp to—yes, a calculator—to your wrist. Much like smartphones, app availability is a good way to determine which product to get, so make sure to check out the app selection for each watch before buying in.
And if you're looking for apps, right now Apple is your best bet. The Apple Watch has the largest number of high-quality apps and big-name developers, by far.