Apple has made its long-awaited entry into the wearables market with a digital watch that can double as a fitness tracker and run a variety of apps.
Called the Apple Watch, it has an oblong glass screen with a curved, touch display and comes in three models -- a standard version with a body made from black or silver stainless steel, a sports version in silver or gray aluminium and a luxury version in hardened, 18-carat gold.
The watch can be personalized to display any of numerous styles of watch face, in traditional analog as well as digital styles. It also runs a wide range of apps, relying heavily on the winder on the side of the watch, known as the crown, to control the interface.
Pushing the crown, for instance, takes the user to the home screen, which displays small, circular app icons in a colorful style reminiscent of the iPhone. The user can touch the screen to zoom in on a group of apps and touch again to open one.
The watches will start at US$349 and be available early next year, Apple said. They'll work with the existing iPhone 5, 5C and 5S, as well as the new iPhone 6 and 6 Plus that were also unveiled Tuesday.
It's the first new product category that Apple has introduced since Tim Cook took over from Steve Jobs as CEO. To launch it, Apple chose The Flint Center for the Performing Arts in Cupertino, California, where Jobs introduced the original Macintosh computer in 1984.
The device puts Apple into competition with smartwatches like Samsung's Gear -- which the Apple Watch resembles in design -- and fitness trackers like the Fitbit and Nike FuelBand.
Cook called it "the most personal device we've ever created."
"We set out to make the best watch in the world," he said.
Apple put a lot of effort into figuring out how to turn the small screen into a workable interface for a device with so many functions. As well as the watch winder, there's a small button below it which, when pressed, brings up a screen showing icons of friends that can then be contacted.
In some of the apps, like Apple Maps, turning the crown zooms the display in and out. The watch will run third-party apps as well as those from Apple, and the company released a WatchKit for developers to build them.
The watch is also a fitness device. An accelerometer measures total body movement, while a custom sensor measures workout intensity by tracking the heart rate. It uses the GPS and Wi-Fi in an iPhone to track how far you've moved.
The watch can receive calls via the iPhone and has a built-in speaker and microphone for "quick chats." Apple recommends taking longer calls on the iPhone.
Some of the more unusual features include the use of haptic feedback for incoming messages, which Apple said feels like a "tap on the wrist," letting you know to look at the device. Users can reply to messages by choosing from a short, pre-written reply or dictating one through the microphone.
The watch also vibrates slightly when the maps app is being used, providing a different feel for left and right, so the user knowns which way to turn without looking at the watch.
Besides the three basic models, Apple is offering a half-dozen straps to suit different styles, including traditional leather, steel links and colored plastics. The watch also comes in two sizes, one 38 millimeters high and the other 42 mm high.
Read our Apple Watch review