I am making, as a Christmas present for my wife (she doesn't read these forums), an easy-to-use LibriVox audio book downloader for her new Kindle Fire. An early version is
here.
Still to be implemented: searching, format selection (currently set to download ogg files; these work great with the Mortplayer Audio Book player).
Hope this forum is appropriate. There is not much about audio books here.
The download is about 2mb, because it includes the LibriVox catalog (as of yesterday). It will also auto-update the catalog every week or so.
The downloaded audio books go into a Librivox directory on your external storage. I may make that customizable in the future. There is also a playlist created for each book in its directory.