As you probably now, your application’s images that are in the drawable directory must be named in lowercase.

Unfortunately this is not true for the iPhone applications. A big portion of my job is to develop Android apps using resources from existing iPhone apps. In order to be quick and efficient, I wrote this bash script that renames all your files in your current directory to lowercase, creates a new folder named 2x (which contains the large images) and removes the @2x extension.

for i in `find .`; do mv -v $i `echo $i | tr '[A-Z]' '[a-z]'`; done
mkdir 2x
mv *2x.png 2x/
cd 2x/
for i in `find .`; do mv -v $i `echo $i | tr -d '@2x'`; done

Please have a backup before using it!