As it has for a number of iTunes milestones, Apple has launched a new contest, this time for the 50 billionth iOS app downloaded. The person who downloads that app will win a $10,000 App Store Gift Card, and the next 50 people will win $500 App Store Gift Cards.

Along with the prizes, Apple has listed the top 25 all-time paid and free apps, for both iPhone and iPad, with Angry Birds, Facebook, Pages, and Skype for iPad at the top of the lists, respectively. As of the time this story was posted, the counter appeared to be at just over 49,207,000,000 downloads; a rough calculation suggests that the 50 billion mark will be hit in roughly 11 days.