The often quoted industry source App Annie has reported mobile app download revenue continuing to increase by 40% in 2016 to $35Bn USD. The estimate of total content revenue which adds in app purchasing and advertising and 3rd party Android app store revenue is $89Bn.
Games dominates the category with 75% of app download revenue in iOS and 90% of Android revenue coming from games.
Statistica reported that in June 2016 Google Play Store had 2.2M apps, Apple App Store 2.0M, Windows Store 0.7M, Amazon Appstore 0.6M and Blackberry World 0.23M.