So, not sure if this is a growing trend or just a nice coincidence, but I just received this message in my FreeSound email:

Your awesome recording was used in the restoration of a 1912 version of Black Beauty for the iPad and iPad Mini called Black Beauty Enhanced. A significant portion of the proceeds supports equine welfare causes and helps stop abuse. A full attribution is in the book, as well. Thanks!

The production in question is available through the iTunes Store.

The original sound that was used is still available through the FreeSound site, of course.