[Question] I have an iPhone 3GS using iOS v4.1, and Jailbroken with Cydia 1.1.9. Is there any way I could get a GBA emulator on it?

I currently have a GBC emulator on it, and use it whenever I'm bored at work (It's easy to carry around!) I'd love to emulate some games that I own if possible. Is there any way? or Can I update my 3GS somehow without losing everything?