The number of smartphone app downloads per year is expected to reach 56 billion in 2013, according to a forecast by ABI Research.

Google’s Android platform is expected to lead with 58% of the total downloads, followed by the Apple’s iOS with a 33% share, while Microsoft’s Windows Phone and BlackBerry are expected to have 4% and 3% shares respectively.

Nearly 14 billion tablet apps are expected to be downloaded by mobile users in the year, with the iPad remaining in the lead with 75%of the apps running on iOS in the tablet segment.

Android is expected to acquire 17% of the annual share excluding Kindle Fire, while Amazon’s tablets are expected to take 4% of the market share and Windows tablets will take about 2% of the market.

According to ABI Research, smartphone developers are expected to implement an Android-first strategy within the year, due to its vast base and generally improved conditions for app building.

ABI Research senior analyst, Aapo Markkanen, said, "Arguably the most pressing issue for Google is how much of this handset momentum will ultimately trickle down to tablets, where Apple is holding the fort remarkably well."

"We would argue that in this context Google will actually benefit from the efforts by Amazon, since the presence of Kindle Fire adds a lot of critical ‘code mass’ to Android’s proposition as a platform for tablet applications. It is worth remembering that Android’s so-called fragmentation problem isn’t only a problem, but that it has a certain upside as well."