Apple completely revamped its iTunes U app last year to include full course materials and it looks like that work is paying off, as the company just trumpeted its billionth content download. Over 250,000 students are enrolled in the service, which now boasts "thousands" of iTunes U learning materials, according to Cupertino. The company added that 60 percent of those downloads came from outside the US, with educators in 30 different countries -- like recent additions Brazil and Turkey -- able to create content. OHU prof "Dr. Fus" Stoltzfus said that students using his materials range from students around the world to retirees, so if you've been thinking of a knowledge upgrade, you've got no excuse. For more, check the PR after the break.