This is a quick example of how Density Specific Resources are used on Android in Appclerator Titanum.  I did  this because I wanted to understand how big my images needed to be for each device.

Here is the summary:
res-xxhdpi (Samsung Galaxy S4) 3x size of pixels
res-xhdpi (Samsung Galaxy Nexus, Samsung Galaxy S3) - Same as @2x images for iPhone
res-hdpi  (Samsung Galaxy S, Samsung Galaxy S2, HTC Desire HD, HTC Incredible S) - 1.5x size of pixels
res-mdpi  (HTC Desire 2.5) - Same as iPhone images (1px = 1dp)
res-ldpi  (people who need a new phone) - .75x size of pixels 

All the apps I have developed are Portrait only, so I dont worry about 'land'

Other things I found out:
There must be a bug in building for the Android device.  Make sure you to a clean before you deploy to your device as sometimes deploying to the Emulator removes all drawables from the build directory.