Over 64% of compatible devices are already running iOS 7, according to Apple, making it by far the company's most successful mobile operating system. In all, iOS 7 was downloaded over 200 million times in the first five days after it was released.
Apple also reported paying developers over $13 billion to date, thanks to the over 1 million apps available in the App Store, which have hit over 60 billion cumulative downloads. (Apple still has the edge over Android; there are about 900,000 apps available in the Google Play store.)