ProGuard

觉得这个很有意思，先记着，找时间好好研究下~

http://developer.android.com/tools/help/proguard.html

The ProGuard tool shrinks, optimizes, and obfuscates your code by removing unused code and renaming classes, fields, and methods with semantically obscure names. The result is a smaller sized .apk file that is more difficult to reverse engineer. Because ProGuard makes your application harder to reverse engineer, it is important that you use it when your application utilizes features that are sensitive to security like when you are Licensing Your Applications.