[This post is by Eric Chu, Android Developer Ecosystem. —Dirk Dougherty]
On Tuesday, we announced that Android Market passed 
10 Billion app downloads.  We wanted to look a little deeper at that huge number.  First question: which app was lucky number 10 billion?  
Photobucket Mobile.  They’ll be getting a great prize package, including tickets to next year’s Google I/O developer conference. 
Remember we still have 8 days left to celebrate 10 billion downloads with 
10-cent apps on Android Market.  You can follow which apps are promoted each day on 
+Android, our Google+ page.
Here’s a graphical deep dive into 10 billion downloads...