Apple announced that nearly a billion applications for the iPhone and the iPod Touch have been downloaded since Apple's App Store went live in early July 2008. The company even introduced a counter to track the number of downloads. It was just in late January that Apple celebrated [1] the download of 500 million applications. Some of the most popular applications include Facebook, Google Earth and the game Crash Bandicoot. Article [2], Slideshow of the top free apps [3], Slideshow of the top paid apps [4].
Links:
[1] http://www.fiercedeveloper.com/story/app-store-tops-15-000-app-mark-800-android-market/2009-01-26
[2] http://www.fiercemobilecontent.com/story/app-store-nearing-1-billion-downloads/2009-04-13
[3] http://www.fiercemobilecontent.com/slideshow/top-free-apple-app-store-applications
[4] http://www.fiercemobilecontent.com/slideshow/top-paid-apple-app-store-applications