48 billion apps have been downloaded from the Google Play Store

"Google said it had passed 48 billion downloads from Google Play, at roughly the same time that Apple said it had reached the 50 billion milestone.
With Google Play having launched well after the App Store, the Android app tally is closing fast on Apple’s cumulative download total. Google said that there have been more than 2.5 billion downloads in the last month alone."

Source:  Mobile World Live, 16th May 2013