A year ago Apple said developers had earned about $7 billion. Now the figure sits at $15 billion total since the App Store first launched.
The number of apps specifically designed to run on the iPad also continues to grow. Last January the number stood at 300,000 native iPad apps, now Apple says there are 500,000.
Apps analytics firm Distimo said in November last year that the Apple App Store was beating the rival Google Play store in app revenue 63% to 37% for Google Play.
(Check out TabTimes Business and Enterprise App Store for a useful collection of apps you can put to work right away)