Everything buyed on Android Market can be tried freely during 15 minutes. if it don't work, then ask for refund.
About CDDA emulation, the best is to be sure you have a .cue and a .bin file called with the same name, in example:
tombraider1.cue and tombraider1.bin, if you have a file tombraider1.img just rename it to .bin.
if this first check failed FPse look too into .cue file to check the name of the image file, but as Android is Case sensitive the name which is in cue file must be the same (letters cases included).
And don't forget to load the cue file and not the bin file.