Default Reversing Android Apps

Hello,

Has anybody here had ago at reversing android apps? I noticed a few people posted "modifications" of games like Flappy bird but that was just changing then GFX file or atlas file which parsed all details about the GFX.

I have spent time analysing some of the game, i used dex2jar so i could read the java, much easier than the reading dalvik opcodes. Has anybody else given this ago?

I got an idea for which the bird class is, where score is stored ect... anybody else?