Releases since February 16th feature button re-mapping, whose menu is available by pressing "R" from the ROM selection menu.
Woah, added just 19 days ago! Good timing on my part! Thank you so much!
I would also like to recommend maybe a mode that changes the colors of the games to make them darker, essentially reversing the brightness filter Nintendo put on all the games to make up for the original GBA not having a backlight. That would be awesome.
Also I downloaded the covers.zip but where do I put it? It's from the GBARunner website that says they are compatible. I just don't know where to dump them on my SD card?