ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. It renames the remaining classes, fields, and methods using short meaningless names.
Does ProGuard work for Google Android code?
Yes. Google’s dx compiler converts ordinary jar files into files that run on Android devices. By preprocessing the original jar files, ProGuard can significantly reduce the file sizes and boost the run-time performance of the code.
Promise to write a tutorial :)
http://proguard.sourceforge.net/
