Apple just announced its year-end numbers for the App Store, and the totals are impressive. Customers spent more than $10 billion at the app store in 2013. It's particularly impressive since some estimates had put 2012 revenue at $5 billion, suggesting revenue may have doubled year over year. Thanks to the holiday rush, December was the best month on record for the App Store, with more than $1 billion in sales and nearly 3 billion total app downloads. Apple developers have now earned more than $15 billion from the store.

The yearly numbers are helped in part by the shift to iOS 7, which saw many established apps undertaking ground-up redesigns to fit into the newly flat aesthetic and often charging users to upgrade to the revamped version. Still, if the numbers are any guide, more than a few users were willing to take the leap. Apple's Eddy Cue, senior VP of internet software and services, applauded the milestone, crediting the success to both loyal customers and innovative developers in turn. "We’d like to thank our customers for making 2013 the best year ever for the App Store," said Cue. "We look forward to seeing what developers create in 2014."