A few notable specials at
www.chirpbooks.com. Chirp is only operated by the app for your phone or tablet and works very well on IOS. I don't have Android device to check it on. You can also play from the website and will remember where you left off. I just saw a notice that if you download the skill for Chirp, you can play on your Echo device as well. There is no way to archive their audiobooks, so keep that in mind. US and Canada ONLY.
A Better Man by Louise Penny $4.99
Mythos by Stephen Fry $4.99
Sinister Magic by Lindsay Buroker $.99
Needled to Death by Maggie Sefton $1.99
Rules of Prey - John Sandford $3.99
Altered Carbon - Richard K Morgan $3.99
One Giant Leap by Charles Fishman $3.99 <--ends today
The Battle for Okinawa by Colonel Hiromichi Yahara $1.99
The Housewife Assassin's Handbook by Josie Brown $1.99 (listed because I just like the title).