One of those tricks is the winder, or digital crown, which Apple demonstrated again on Monday. Turning it lets you zoom in and out of maps or scroll through messages, and pushing it takes you to a constellation of colorful app icons on the home screen.
Also novel is the "taptic engine," which notifies you of a new message with a tap on the wrist, but also works with other apps, like maps -- when you're walking down the street, one type of tap on the wrist tells you to turn right, another type to turn left.
There are also unique ways to communicate. Digital Touch lets you draw a picture on the screen that appears on a friend's device right away. And if you press two fingers on the screen, the built-in heart rate sensor sends a recording of your heartbeat. Apple calls it an "intimate" way to say hello.
The watch is obviously a timepiece, too, with a huge variety of digital and faux analog displays to choose from. It's also a fitness tracker, with built-in components that measure your activity and pulse rate.
There's no keyboard, but you can dictate messages using voice recognition, or send an audio recording. There's also a clever text analysis engine that reads incoming messages and formulates pre-written replies. So if someone asks if you want "Italian or sushi", the watch prepares replies that you can choose from and send back to answer that question.
We already knew the watch works with Apple Pay, and in September Cook talked about an app from Starwood Hotels that will let you check in and open the door to your hotel room using your Apple Watch. That will be available in all W hotels in the spring, he said at the time.
Another app from BMW will show you a map of where you parked your car, in case you forgot, and an app from Honeywell will let you set the temperature in your home. Others are in the works from Pinterest, Nike, Major League Baseball and Citymapper, Cook said.
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