The basic android application structure as per intelliJ(Android Studio) is as below
app -->(manifests, java, res)
manifest --> AndroidManifest.xml
java --> <package> --> all java files
res --> (drawable, layout, menu, values)
drawable --> (*.png, *.xml)
layout --> (*.xml)
menu --> (*.xml)
values --> strings.xml
Actually this structure is abstracting all other unwanted folders/files from the development activities like R.java(generated dynamically) ..etc.
This structure looks easy of understand internal resources easily.
I hope this structure helps for developers who already worked on Eclipse IDE. (Even for me too :) )