As if there was ever any doubt.

With Apple recently announcing its ten billionth app download, it’s clear that 2011 will be the year of the app. Smartphones are nearing ubiquity and it’s estimated that 18 billion apps will be downloaded in 2011, with consumers spending over $15bn in the process.

If you’ve focussed all your efforts so far on designing for all the Apple-lovers out there, it’s probably time you broadened your horizons a little…for European customers, at least.

Google’s Android is now the UK’s number one smartphone operating system, with March figures showing that Android accounted for 38% of all smartphone sales that month.

And it’s a real turnaround in fortunes for Android, given that this time last year it had less than 9% of the smartphone market sewn up.

And if you’re thinking that Apple surely must be a close second to Android…think again. Blackberry’s RIM actually held second place with 24.5% of smartphone sales in March, an increase of 7.5% on the same period in 2010.

Curiously, Apple’s iOS fell 16.5% on the same period in 2010, and the iPhone now constitutes less than a quarter of all smartphone sales in the UK.

Nokia’s Symbian platform dropped by about 15% on the previous year, but its recent partnership with Microsoft could see it challenge the top dogs in the next twelve months. Nokia, unlike Apple or Android, doesn’t typically have what’s known as ‘early adopters’ in its core customer base, so a handful of nifty Windows devices in the next year or two will probably see Nokia regain some ground in the smartphone market.

Elsewhere in Europe, it seems that Android is also stealing the limelight, with both France and Germany reporting similar levels of uptake for Google’s mobile OS to the UK.

So, Android is the way forward for smartphones, it would seem. But don’t let these figures fool you completely. When you factor in Apple’s tablets and iPods, then market share in terms of OS rather than device will probably look a whole lot different. Plus, these figures don’t reveal app-downloading or online engagement habits of users. Apple typically has a much more web-centric customer.

But it does show that app designers need to focus on multiple platforms, not just Android or Apple. And these figures also show just how big the app market is for all the designers and marketers of the world.

So, if you’re a business looking to create your own app, why not submit a brief to our global Crowd of app designers? Or if you’re an app-designer looking for your next design brief, why not join our crowd?