Free Audiobooks – Audiobooks.com: Get audiobooks Review

The app seems easy enough to use but I have a question before I rate the app. I downloaded this app for the free audiobooks. But is there a monthly fee for the use of this app if all I do is listen to the free audiobooks? The app didn’t mention anything about in app purchases.
Review by Barb 123 on Audiobooks.com: Get audiobooks.