I am so happy I can finally post some good freebies! I've been keeping my eye on these for a couple of weeks (I stumbled on them in the app and thought they were pricing errors). When I logged onto the web site today (where it is normally impossible to identify what is free and what is not) I spotted some lists of free titles in their "Deals" section. Most of these are perma-freebies from other sites like Librivox or Thought Audio but there are also some freebies from Tantor audio sprinkled in as well. Here are the links to the lists.
Enjoy!
skinmaan
Your audiobook bloodhound