Apple's Watch - what's it for?

Apple Watch Image copyright Justin Sullivan

Finally, four years after the iPad, and after endless rumours about the reinvention of television and other industries, Apple has launched a brand new product in the Watch. It is a long way from being the first in its field, but as with the iPad, the iPhone and the iPod, could it redefine the category and send huge new waves of cash to Cupertino?

I'm sceptical - not about Apple dominating the smartwatch market but whether it's ever going to be that valuable a business. Yes, by next spring the Watch will almost certainly be the market leader. By announcing it in September and not delivering until 2015, Apple has ensured that consumers will look at rival products over the next few months and think it is worth waiting for something better.

And it is a very good-looking gadget. Jony Ive and his design team have been working on this for at least three years, obsessing over every detail, learning from the mistakes of rivals before unveiling their work. And it will get better over the coming months, now that outside companies can be brought in to work on apps.

But the big troubling question is quite simple - what is it for? What added utility will it bring to our lives? During the launch we heard some examples - a tie-up with American Airlines, which would mean you could carry your boarding pass on your wrist, a hotel app, which would allow you to access your room with a swipe of your watch. You can also get notifications of emails and messages, check your pulse, count your steps, control the music on your phone or speakers or use it as a remote for your Apple TV box.

But all of the above actions have one thing in common - you can also do them with a smartphone - in many cases a lot more easily. Apart from some of the fitness monitoring capabilities, it is is difficult to think of many things that are done better on a watch face than on a smartphone screen.

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Media captionWATCH: Can the Apple Watch convert a sceptical public to wearable tech?

Still, the fashion journalists invited to the launch seemed enthusiastic, praising the way the watch could be modified according to your personal tastes. At $349 (£216) it looks expensive, but then people pay a lot more than for fashionable watches - although they don't have to plug them in every night to recharge.

One key test for any new product must be whether you would feel the need to turn around if you had left it at home. For many of us that is definitely the case with a smartphone, but having tried a couple of smart watches I would have no problem living without one for a day.

Perhaps Apple can really find some killer app for its watch - I was gratified to see that my speculation about its use as a payments device turned out to be accurate. But I would not mind betting that in a few years time the market analysts will still be focusing on the iPhone's profit margins, while seeing the Watch as a nice little earner but one that can be safely ignored.