Facebook sees more than half a billion Android connections per month from >10,000 different device models

"The rise of Android phone usage around the world in the past few years has been staggering. Facebook now sees more than half a billion people connect each month from more than 10,000 different Android device models. As we've restructured mobile development to be owned by each individual product team within the company, we have kept small groups of people focused on developing a deeper understanding of each platform in order to provide common tools and knowledge so we can avoid re-inventing the wheel."
Source:  Facebook Code blog, 6th November 2014