Crunch is a simple yet powerful utility to extract the content of iOS application files (.ipa or .app file extension). The result is exported in a folder and then you can browse in the Finder any file present in the application package.
Features:

iTunes Library: Visually browse all of the apps of your iTunes library without leaving the app.
Drag & drop: Simply drag one or more apps onto Crunch to export them.
Export options: Crunch has powerful export options :
Filter : Export only the images or the media files.
Export only the high resolution images (images in the retina resolution).
PNG Images Normalization: PNG Images in an iOS application have been optimized to process them faster but they are no more compatible with OS X. Crunch is using a tool provided by Xcode to revert the optimization. So you can look at the native PNG files. To use that feature, Xcode must be installed on your Mac (Xcode is free available on the Mac App Store).
Quick Look: Crunch has a Quick Look plugin for iOS application files (.ipa files). The Quick Look plugin generates thumbnails for the Finder icons (+ an optimized thumbnail in Cover Flow mode) and gives you access to a preview panel that displays all the main informations about the file.

System Requirements:
Intel
Mac OS X 10.7 or later
64-bit processor