The iOS App Store is about to reach 10 billion downloads, Apple has announced. As has become traditional for major iTunes milestones, the company is hosting a contest in which the 10 billionth app download -- or a form entry received after the 9,999,999,999th one -- will win someone an iTunes gift card worth $10,000 US. Despite the currency value, the contest is open to anyone 13 or older in a participating country with an App Store.