As others have mentioned, as long as it fits on my storage card. The problem I've seen with some apps is that they need to install a DLL in the \windows directory, even though the program is on the SD card.

Right now with Fish Tycoon it still puts the save file in My Device\Program Files\Fish Tycoon despite me installing to my SD card. Need to use registry entries for finding and saving of all files.

-al