Multithreading sucks

After placing and sometimes tossing around synchronized blocks cluelessly, it looks like I finally managed to get the multithreaded program working nicely, smoothly, and properly on both PC and Android. However, I'm planning to take closer looks at how I synchronized the code and make a few more tweaks. Hopefully I don't screw up the code that I seemed to have made it work. Was that grammatically correct?