I had a horrible experience with Amazon (and thus Audible) a while back, they closed my account and I lost access to all books that I have not backed up (which were not many fortunately). Since I listen to audiobooks a lot (driving, loading dishwasher, walking, ...) and I prefer to backup and be DRM-free, I was looking for an alternative. I settled up with libro a while back already, but yesterday I realized I am buying so many audiobooks that the $14.95/month membership makes more sense than paying per book.
The books come in m4b format a mp3 in zip format. I use Smart Audiobook Player on GrapeheneOS and have previously used MP3books on iOS. You can also use their app if you want.
If you want to free yourself from overly controlling corporations and be able to listen to audiobooks you paid for without permission, I highly recommend it:
