http://plusd.itmedia.co.jp/pcuser/articles/1204/12/news074.html
http://blogs.msdn.com/b/b8_ja/archive/2012/03/29/10289089.aspx
http://wired.jp/2012/05/29/android-fragmentation-one-developer-encounters-3997-devices/
http://opensignalmaps.com/reports/fragmentation.php
