Apple's App Store has generated 15 billion downloads since its launch in July 2008, Apple has announced.
The App Store now offers more than 425,000 apps, 100,000 of which are created specifically for Apple's tablet, the iPad.
Apple has paid developers more than $2.5 billion to date. Given Apple's 30/70 revenue split with app developers, that means Apple itself has netted more than $1 billion directly from app sales.