In the buildup to tomorrows Google I/O conference, App Annie has released a report detailing the rapid growth of Googles Play Store and the revenues its producing. After surpassing a million apps last summer, Androids app repository now has more than 1.5 million, with downloads reportedly growing by 50 percent between 2013 and 2014. Income from those apps is increasing at an even faster pace, more than doubling last years totals. Whats notable about that growth is that its being driven almost entirely by freemium apps — free to download, but including paid in-app purchases — which now produce 98 percent of all revenues from Android apps and games.