http://www.iteye.com/topic/1128878
http://developer.android.com/training/basics/supporting-devices/platforms.html
http://developer.android.com/training/multiscreen/screensizes.html#TaskUseSizeQuali
http://developer.android.com/training/multiscreen/adaptui.html#TaskDetermineCurLayout
http://developer.android.com/design/style/metrics-grids.html
http://developer.android.com/design/style/iconography.html