Crystal Defenders android hack.

[InfamousKnight]

I have some experience with java and other programming languages like C/C++, asm, python, etc. I would like to add another job class in the game called the Ninja that has high speed and low attack power. Would I just extract the apk file and find its source code? I'm feeling very confident about this.

[Klarth]

I'm not feeling very confident about this.  If you have some experience with Java (Sun Java, not Javascript), then you know that Java source code is compiled into Java bytecode for the Java Virtual Machine to interpret/JIT compile to native assembly code.  You won't find source code inside, just lots of Java bytecode.  It's probably not a feasible project without a good debugger and it's probably not worth the several dozen (or hundreds) of hours required to implement unless this is your favorite game in the world.