Well, it's Gambatte that is the backend and running the game, PyBoy is just Gambatte and my front end packaged together (insanely painful to package). But, yes, it's the best Game Boy emu available for the tablets to date
I've been mucking about with this for my first Maemo project. I've yet to get the packaging figured out, but here are the files in case anyone wants to do it by hand. So far I have added some touchscreen buttons, the bottom half of the screen is A and the top half is B. It now runs fullscreen, so it can use Xsp pixel doubling for the 2x mode which seems to be a bit faster. The + and - buttons now control the volume. In the future I'll make all this stuff optional. But for the moment this is a heap more playable IMHO. Here is the source and binaries, you should be able to just dumb the binaries in /usr/bin and use pyboy as before.
Oh yeah and another thing, if using the 2x mode, make sure to exit using the return button, anything else will dump you to a mangled desktop due to the pixel doubling. I'm not sure what I can do about that.