Most of the really common images in iOS are tucked away in .artwork
files.
These files typically contain hundreds or thousands of images, all rolled into
one file. I assume Apple does this for performance reasons. If you have an iOS
SDK handy, you’ll find a number of .artwork
files lying around.
My iOS Artwork Tool can both extract images from, and import images into,
.artwork
files. You don’t need to be a registered iOS developer to use the
tool — it’s a simple Python command-line app.
I’ve just updated the tool to support iOS6. As it turns out, a lot of things
changed. There are now two different .artwork
formats: a hard-to-crack
old-style format found in iOS5 and earlier, and a surprisingly easy-to-crack
format introduced in iOS6. The tool now supports both formats.