Apple PR:

Apple® today announced that customers have downloaded over 40 billion apps*, with nearly 20 billion in 2012 alone. The App Store℠ has over 500 million active accounts and had a record-breaking December with over two billion downloads during the month. Apple’s incredible developer community has created over 775,000 apps for iPhone®, iPad® and iPod touch® users worldwide, and developers have been paid over seven billion dollars by Apple. *40 billion unique downloads excluding re-downloads and updates.

Great success for Apple. Half of these downloads happened in 2012 only, that’s crazy. The App Store is a strength for Apple. Difficult to replicate as Microsoft and RIM know.