Apple Watch was the leading smartwatch in the second quarter, with an estimated 4 million shipped worldwide, for a market share of more than 75 percent, according to Strategy Analytics. Samsung was a distant second with 400,000 shipped and a 7.5 percent market share.
However, the market is still nascent, and Apple Watch isn't an option for people who use Android smartphones.
Samsung's Gear S2 will work on Android - and for the first time, not just Samsung's Android phones. Meanwhile, watches running Google's Android Wear software will now work with Apple's iPhones.