I hope the game is going to be awesome with spanish.
I can help improve the game's perfomance too.
You can use Dropbox to save your files too
EDIT: I don't know if Dropbox turns .png files into .jpg
First of all, I don't mind much about .PNG and .JPG fiasco, because I use Google Drive instead, which doesn't change images when uploaded.
Secondly, if you want to improve the game's performance, I hope that you know how to program in Java and Smali. Because I don't know how to program in those languages and I didn't found anyone who can develop projects using those languages. Especially for free. For that, I'll say good luck !