In conjunction with Apple's recently-announced countdown to 50 billion app downloads, the company last week issued an updated list charting the most popular iPhone and iPad apps of all-time. Per usual, the listing is broken up between free and paid apps. As one might expect, the list is extremely game heavy, with Rovio's Angry Birds making a number of appearances on both the paid and free list. It's also worth noting that a number of Apple's own applications make appearances on the list of most popular paid iPad titles.
So without further ado, let's take a look at the apps that iOS users simply haven
