Update: We tested Apple Watch here and note that apps start development in November. See the official iPhone specs below, including battery life and anti-theft features.

Apple CEO Tim Cook had a big "one more thing" announcement up his sleeve, and it was a small sapphire-coated smartwatch dubbed the Apple Watch, not the fabled iWatch.

This iPhone-compatible watch was unveiled alongside the iPhone 6 and iPhone 6 Plus, fulfilling the Cupertino company's "new product categories" promise for 2014.

It's not a circular smartwatch like its fashionable rival, Moto 360, but it still features a premium rectangular design with rounded-off corners and works seamlessly with iOS 8 devices.

Cut to the chase
What is it? An iOS 8-friendly watch that plays nice with your iPhone
When is it out? Early 2015 release date
What will it cost? $349 (likely north of £217, AU$379)

What does Apple Watch do?

Apple's first wearable gadget beams messages, Facebook updates, simplified apps and Siri to our wrists, eliminating the all-too-common need to take out our devices to constantly check notifications.

It's going to become especially convenient to pocket the 4.7-inch iPhone 6 and even bigger 5.5-inch iPhone 6 Plus in your jeans, or to always stow the next 9.7-inch iPad Air 2 in a bag.

Apple Watch apps
A handful of the Apple Watch apps being demoed

Other apps seen in the Apple Watch video include iMessages, Health, Calendar, Weather, Mail, Photos, Camera's shutter button, Passbook that now includes Apple Pay and even Apple Maps for navigation.

Developers will be readying more Apple Watch apps in the coming months thanks to the November launch of the WatchKit SDK next month. It could bring a whole new section to the iTunes App Store.

The smartwatch also takes cues from the Nike FuelBand SE and other fitness trackers with health sensors and nutrition apps, a must for any serious wearable gadget these days.

Sure there are fitness apps on your smartphone, but you're not always carrying your iPhone while tracking your steps and activity. The Apple Watch is better suited for your everyday workout.

Design

The final Apple Watch design isn't too far from the made-up renders that we've seen in recent weeks. It draws inspiration from iPod Nano with a rectangular-shaped screen plus one knob and a single button.

Apple Watch is more than iPod Nano meets the iPhone, though. The smartwatch display comes in two sizes measured by height: 38mm (1.5in) and 42mm (1.65in). Both are slightly smaller than the entire Pebble Steel watch height, which measures 46mm (1.8in).

Apple Watch design
Here's the Apple Watch design from all angles

Apple Watch's screen is surrounded by casing made of custom alloys of stainless steel and aluminum that, according to the company, stands up physical demands of daily wear and another BendGate.

Beyond the "Apple Watch" and "Apple Watch Sport" versions, a special "Apple Watch Edition" mixes in 18-karat yellow or rose gold for a premium look. It goes well with that gold iPhone 5S for sure.

Apple Watch collections
Three Apple Watch 'collections,' each with two sizes

That brings the metal colors to six: stainless steel, silver aluminum, space black stainless steel, space gray aluminum, 18-karat yellow gold and 18-karat rose gold.

Digital crown

Apple Watch doesn't have a unique round display like Moto 360, but the casing does feature a circular knob known as the "digital crown."

This input is unique among smartwatches, but a true classic derived from traditional watches. Apple has of course put a modern-day twist on its twist functionality.

Apple digital crown
Apple invents a new control scheme using a classic input

The Apple Watch digital crown replaces the pinch-to-zoom touchscreen mechanic used on everything from iPhones to MacBooks. It's too impractical on such a small display, according to Apple.

Rotating it allows you to zoom into your app selection, your location on Apple Maps and a photo from a gallery. Scrolling through dates and stopwatch times is handled by this knob too.

The digital crown also acts as the Apple Watch home button. There's no Touch ID sensor here, but Apple is smartly locks the wristwatch with an anti-theft passcode whenever it's taken off.

Conversation button

The button below the digital crown allows you to start a conversation with friends. Pushing it brings up a their contact info photos and zooming into a specific person with the digital crown gets things started.

Beyond calling and messaging them, you can get their attention with a gentle tap. It vibrates the "taptic" feedback on their smartwatch.

Apple taptic conversation
Communicate with simple vibrating taps or sketches

What's intriguing about this taptic feedback system is that it's said to be more precise and subtle than a vibration everyone can hear. Want to ditch a party? Your friends' secret sign may be three taps on the Apple Watch before bailing. It's an interesting way to get someone's attention.

Apple Watch goes all Drawesome on us with a bizarre sketch function for light messaging on the wrist. You can also share your heartbeat with someone in real time.

Apple Watch bands

The variety of Apple Watch bands played better than U2 at the press conference, giving consumers a way to personalize their smartwatch.

Standard straps include Leather Loop that conceals magnets for easy fastening, the leather Modern Buckle and the leather Classic Buckle. There's also a gym-friendly elastomer Sport Band.

Apple Watch straps
Apple Watch straps are easy to swap out

Higher-end metal straps include the Milanese Loop with flexible magnetic stainless steel mesh and the stainless steel Link Bracelet.

The ability to swap the straps without having to use tooling or visit or jeweler is one of our favorite features in the Apple Watch vs Moto 360 comparison.

Apple Watch faces

Apple is promising customizable watch faces with "millions of different appearances." It brings everything to its timepieces, from time lapse backgrounds to classic Mickey Mouse arms as dials.

The first six Apple watch faces
The first six Apple watch faces

However, just to be clear, the smartwatch comes with a base of 11 watch faces, according to the official Apple Watch press release. Most allow you to change the colors, design elements and add functionality.

The Apple Watch face gallery shows off an Astronomy design with an interactive, real-time 3D model of the earth, moon and planets. Likewise, the Solar acts as a contemporary sundial.

Apple watch face images
I can finally get myself the Mickey Mouse watch I always wanted when I was six

If you want a moving background, there's the Motion watch face, or still image, there's the Photo face. Utility, Chronograph, Color, Modular and Simple exhibit more contemporary designs.

Apple Watch battery life

Tim Cook didn't go into great detail about the Apple Watch battery life, but he did hint that the smartwatch is designed to be "worn all day" and is "simple to charge at night."

That had led us to believe that the Apple Watch will approximately have one day battery life, sort of like the Moto 360, LG G Watch and Samsung Gear Live we've reviewed.

An Apple spokesperson backs up our theory, more or less confirming that the smartwatch requires a daily charge. The person also reportedly said Apple is working on modifications to eek out more battery life.

Apple Watch battery life
Easy to connect like a MagSafe power adapter

Previously, when it was known as the Apple iWatch, it was rumored to have a 400mAh battery, but Cook is saving that announcement for a later date.

He did, however, call attention to the unique recharging method. The Apple Watch's back crystal houses a magnetic inductive wireless charging solution similar to the MagSafe design. Again, it looks as if Apple bucks another trend - this time it's the popular Qi wireless charging method - in favor of its own standard.

Release date

For a gadget that supposedly keeps the time, the Apple Watch release date speculation has been all over the place. It highlighted the fact that no one outside of Apple had the full scoop until September 9.

Just don't expect that to be the iPhone-compatible watch's release date this year. Apple's official line is that it won't deliver the the Apple Watch until early 2015.

Reports in the Taiwanese media have placed the release date as sometime in February. Those same reports suggest manufacturing of the Apple Watch has slipped to January due to Apple being constrained by the amount of sapphire that supplier GTAT is able to produce for the device's display.

This could mean that when the Apple Watch does arrive, there could be less than the targeted 10 million smartwatches the company may want for the launch window. Although it's important to bear in mind that Apple's entry-level model, the Apple Watch Sport, doesn't include a sapphire display.

This may mean that while numbers of the Apple Watch and Apple Watch Edition versions are less than expected, the company can still produce enough Apple Watch Sport models.

Apple Watch release date
Don't expect to see it alongside the iPhone 6 and 6 Plus this month

And yet, the early Apple Watch unveiling makes sense. Google's first smartwatches have just been released care of the Samsung Gear Live, LG G Watch and newly-launched Moto 360. None work with iPhones.

A sneak peek at the iPhone 6 event makes the watch right on time, enough to distract people from even prettier Android Wear watches to come, like the LG G Watch R.

Apple will be working hard to avoid the same kind of limited supply problems it faced when introducing the hot, but hard-to-find gold iPhone 5S last year.

Price

An even trickier question than "when will it come out?" has been "how much will the Apple Watch cost?" There's really no precedent for a premium smartwatch price just yet.

The answer: More than we were hoping to pay, even though its specs may be on par with Android Wear.

Apple Watch
It's classy, but the starting price is out of some peoples' budgets

That notorious Apple tax pushes the pricetag to $349 given components involved. That's £217 in the UK and AU$379 in Australia, but expect those prices to be even higher, above the straight dollar conversion.

It's true that Apple has recruited high-profile people throughout the watch and biometrics industries who have wound up on its Apple Watch team. That talent comes at a price.

Then there's a hidden cost. While a subsidized iPhone 6 and iPhone 6 Plus are cheaper upfront in the US, stores make up the difference with contract kickbacks. Not so with a smartwatch. Stores need a cut too.

Apple watch price
Apple Watch cost way more than your average fitness tracker. Are you willing to pay?

For the sake of comparison, Android Wear's cheaper options are the Samsung Gear Live at $200 (£170, AU$250) and LG G Watch at $230 (£160, AU$250).

But Apple's biggest and most stylish competition is from Motorola, and the Moto 360 price is $249 (£199, likely AU$275 given its rivals' prices).

Apple is aiming for luxury given the sapphire glass-protected display, an imposing digital crown, two sizes and even the 18k gold colored edition. Expect prices for that version to climb even higher.