With app stores the hot industry topic, Ovum's new report about what it calls non-operator application stores looks timely.

It predicts the sector will grow at a compound annual growth rate of around 41 percent globally over the next five years.

Total downloads are estimated to reach around 21 billion by 2015, up from 2.7 billion in 2009.

Perhaps what's more significant is how the company mix will change.

Bite out of Apple

At the moment, Ovum reckons Apple takes 67 percent of smartphone app downloads, despite only having 14 percent of the overall smartphone installed base. In contrast, Symbian has 49 percent of the smartphone market but only accounts for 9 percent of downloads.

The report states in 2015 Apple will generate 22 percent of app downloads, compared to 19 percent for Symbian.

One of the platforms that will affect this change is Google's Android, with Ovum expecting it will increase its smartphone base from 5 percent to 18 percent and its share of app store downloads from 14 percent to 26 percent.

Rising tide

The report also reckons platforms such as Windows Mobile and BlackBerry will lose smartphone share over this period but increase app downloads. BlackBerry is predicted to rise from 5 percent to 17 percent for example.

Michele Mackenzie, principal analyst at Ovum and report co-author, said: "The iPhone generates the lion's share of smartphone app downloads but over the period we will see the share of application downloads becoming more equally distributed.

"Over the forecast period other smartphone platforms gain ground and by 2015 the landscape looks very different in terms of market share."

[source: Ovum]