A search of "volume boost" in the market brings up several options, but many (most?) of them seem to be device specific, so some research would need to be done.
Personally I've not tried any of them, never actually used a headset with the TF. As close as I've come is plugging it in to some PC speakers to get decent sound while I was watching a movie. They were powered speakers so I didn't have any problem getting enough volume.