Apple iWatch: the rumoured release date is 9 September so here's everything we know about Apple's fabled smartwatch

We've only rumours and reports to go on, but expect a fashionable device with a focus on fitness tracking, voice commands and smart home control

Apple iWatch concept renders (Todd Hamilton)

Apple is reportedly planning to unveil its iWatch on September 9th alongside two new iPhones, offering users fitness tracking via new platform HealthKit and the ability to control their smart home via HomeKit.

This is just the latest speculation regarding the semi-mythical wearable (albeit from an unusually credible source, Re/code’s long-time Apple watcher John Paczkowski) but just what do we really know about Apple’s smartwatch? Let's take a look.

Firstly, it’s a real thing.

Apple has been under pressure to introduce a new product category for a while now, and when CEO Tim Cook declared in May 2013 that the wrist was an “interesting” place for tech, this seemed like a clear indication of where the company was headed.

Since then numerous manufacturers (from big dogs like LG and Samsung to independents like Pebble and Cookoo) have jumped into the arena, and Apple has responded with a hiring spree (nabbing fashion-focused executives such as former Yves Saint Laurent CEO Paul Deneve) and securing the ground patent-wise (eg extending the Apple trademark to cover “jewellery, clocks and watches”).

However, as Cook said last year about wrist-bound tech: "I think for something to work here, you first have to convince people it's so incredible that they want to wear it." Thus all the build up and all the speculation: Apple wants to get it right first time.

Other manufactureres like Pebble have already released several smartwatch iterations.

But we have no idea what it will look like.

Will it have a square screen or a round screen? Curved or straight display? We really have no idea. There's been conflicting reports, a number of imaginative mock-ups and even a few odd patents from Apple (one of them as a 'slap bracelet').

The WSJ has claimed that it will be available in "multiple screen sizes" and offer "more than 10 sensors"; the New York Times has said it will most likely use "curved class" to fit round the wrist; and the screen size has been variously reported as 1.3-inches, 1.6-inches, 1.7-inches, 1.8-inches and 2.5-inches. So what can we conclude?

Well, it seems a good bet that there will be multiple variants (watches, unlike smartphones, really don't work as one size fits all) but as to styling, it's anyone's guess. Will Apple's current yen for glass and aluminium feel at home on the wrist, or could they switch to traditional styling, offering leather straps and round watch-faces (that's the idea by designer Gábor Balogh). We'll have to wait and see.

We know health and fitness will play a big part.

Although consumers have been far from enthusiastic about smartwatches that act as second screens for our smartphones, fitness wearables have been adopted enthusiastically and Apple is expected to capitalised on this.

The company has already announced 'HealthKit', a new health-focused platform and app for iOS that is capable of gathering together all sorts of biometric data, and many of their new hires have focused on this sort of expertise.

With this in mind, the iWatch can be expected to count steps, calories, monitor sleep, measure heart rate and possibly even dive into more exotic categories such as measuring haemoglobin levels and oxygen saturation (though this is not very likely).

The nearest Apple has come to 'making' a wearable are wrist-bands for the iPod Nano (pictured).

And home automation too - although other features are less certain.

Also on the cards for the iWatch is HomeKit - another newly-announced app/platform that will be arriving with iOS 8, but one that's dedicated to controlling smart home appliances, that is, internet-connected light bulbs, thermostats, and yes, even fridges.

With this in mind, it also seems fairly certain that the iWatch will hook up to Apple TV - the company's set-top streaming box - and that Siri and voice commands will play an increased role (you might not like to 'ask Siri' things in public - but in your own home, asking a robot flunkie to turn off the lights would be embarrassment free).

Other hardware options are less certain, although a wireless charging option would be a good fit (and a possible compensation for a less-than-sterling battery life) and NFC tech (near-field communications) could allow it become a payment device.

Apple's HealthKit will offer a central clearing house for keeping track of health data.

It's coming soon - but price is anyone's guess.

There's no guarantee we'll see the iWatch next month, and even if we do, it might be a while until its available to buy (there have been multiple reports of problems in the supply chain, mostly due to the difficulty of manufacturing tough, sapphire screens and getting the most from a tiny a battery).

In terms of price as much as we'd love to see something relatively cheap (after all, the Apple TV goes for just £79) but this is Apple we're talking about, and the price is bound to reflect the months and months of R&D and presumably the fashion-focus. Competitors' prices hover around the £150/$250 mark so expect this as a baseline.