There was much cause for celebration in Cupertino, California recently as the iPhone app store’s much-vaunted download ticker clicked over the 10 billion mark. The typically bombastic figure reflects just how dominant Apple is in the smartphone market.

But this might be changing, as ‘Apple fatigue’ sets in and the one company that can challenge the iPhone’s ubiquity continues to make ground in key markets. At the heart of it, Google’s Android operating system has an increasingly trusted name – along with the reassurance of partnerships with established handset manufacturers – and gives consumers the customisation and apps of the iPhone, at a lower price point and with greater handset choices.

Add to this is a perceived reaction against Apple’s market dominance – the “anyone-but-Apple” brigade – and the reasons for Android’s surge in market share start to look increasingly like a trend. Currently, much of Android's success appears to come from being the alternative, winning over those who have specifically chosen not to buy an iPhone.

The operating system (OS) market is currently comprised of three main players: Apple, BlackBerry and Google, and the market is still growing. According to handset manufacturer Ericsson, by the end of 2011, one billion people will be connected to the mobile web. In another quantum shift, smartphone sales have now surpassed PCs in overall sales.

One of the main complaints about Apple’s handset is the amount of control over what is permitted on the device. In contrast, the Android OS is championed as being open-source, versus Apple’s closed, proprietary iOS system. This means that Android users have access to multiple app stores, and there are no app developer restrictions. In addition, the OS isn’t restricted by Apple’s aversion to Adobe, meaning that Flash is an oft-utilised feature of Android-developed apps.

What makes the comparison tricky though is that there is a stable of Android-enabled handsets, as opposed to Apple’s single phone (although the iPhone is currently in its fourth iteration with a fifth on the way). Having this wealth of options – from price to battery life – through competing handset manufacturers is an attractive benefit for many Android champions. It has been rumoured that Apple is seeking to develop a cheaper iPhone to combat at least one of these concerns.

In what might be considered a repeat of Apple’s battle with Microsoft in the 1990s, there is a disparity between a user-friendly interface and general intuitiveness in the phone’s functions, and the width and breadth of available apps. In this case, the Apple iOS is clean and its usability immediately apparent whilst the Android also lacks Mac’s signature slickness when it comes to interfacing.  

Google’s mobile OS has had considerable success in China, and the spoils are significant. The country has a whopping 800 million mobile subscribers, and smartphone sales are on their way up. "Our latest visit to China made it clear that Android has become the faraway leader in mobile operating systems," Deutsche Bank technology analyst Jonathan Goldberg wrote in a recent edition of the industry’s Digits newsletter. Investment bank Piper Jaffray analyst Gene Munster forecasted that globally there would be 133 million Android users by 2012.

Android-installed handsets overtook iPhone sales in the second quarter of 2010, and have continued to increase market share. However, US mobile carrier Verizon has recently added the iPhone to their roster, which is expected to slow Android sales in that market.

There are currently over 350,000 apps available on Apple’s app store. While the exact figure is hard to calculate given the speed at which new ones are developed, the Android app count is catching up. At the end of 2010, AndroLib.com reported that there were 200,000 apps for phones running Android. It also revealed that collectively these apps had been downloaded more than 2.5 billion times – a quarter of Apple’s celebrated milestone. In the past few months this figure has of course increased as developers continue to take advantage of the open-source nature of the Android system, and while they still lag behind Apple, this figure is set to expand even further. All of this means Android’s reputation as the iPhone killer may be coming to fruition. At least, enough to take a bite.