A rather strange application for GP32 is GpKat. Here is what the author says:

It may not look like much but that doesn’t matter – it’s the sound thats important. Basically what we have here is a tool for annoying interacting with cats. First find a cat. With cat in place and GpKat loaded up on your GP32, press one of the buttons, move the joystick and one of twenty possible cat noises will sound out. Your cat may be confused and try to find the”other cat”. Or cats being cats, it may just give you a dirty look or simply ignore you. Either way, it should provide literally seconds of amusement! toxicbreakfast.com takes no responsibility for feline related injuries or animal psychiatry bills resulting from use of this application.

http://www.toxicbreakfast.com/tb/downloads.shtml