Apple Watch (1st generation)

Apple's first new product category after the iPad, and for about a year nobody was sure what it was for. Apple launched it as a fashion object, with a gold Edition model at $17,000, Vogue covers and a Paris store opening, and spent the first year discovering that people wanted a fitness tracker and a notification screen rather than jewelry. The hardware was slow. The S1 struggled with third-party apps, which loaded over Bluetooth from the phone and could take long enough that you put your wrist down. Everything you might want to do took a beat too long. What worked immediately was the Taptic Engine, which tapped your wrist rather than buzzing, and the activity rings, which turned exercise into three circles you wanted to close. Those rings have survived every redesign since and are the thing most Watch owners actually use it for.