I am trying to use progurard with my android applications. The proguardGui accepts an input, and an output, the input requires a jar file. but the APK file for android doesn
I detailed complete instructions on how to do it here: http://www.androidengineer.com/2010/07/optimizing-obfuscating-and-shrinking.html
Basically, you have to first set up an Ant build for your Android project, which is relatively painless. Then, you add in the ProGuard Ant target between the Java compilation step and the DEX step. Remember, ProGuard only works on Java bytecode, and Android uses the Dalvik JVM which uses .dex bytecode, so that's why it happens between those two steps.
Actually the Android SDK already integrates ProGuard.
You only need to uncomment the line "proguard.config=....." in the file project.properties (created or updated by Android SDK 17 or higher), in order to enable ProGuard.
Source: ProGuard examples -> a complete Android Application