Please post wisdom about AudioLayer here. Discussion of AudioLayer other than knowledge sharing that would go in a wiki belongs in a discussion thread.
A great place to start if you are having trouble figuring out how to import EXS files into AudioLayer is this video from the AudioDabbler:
and this thread (which has a great trick if you are not see the AudioLayer folder in Files on your ipad):
@Lithalean has shared some nice instruments, here:
(Notice that a few of these are sfzs which you will have to convert to EXS)