Overdrive is one of the many services -- though it was the first -- to provide digital content to public libraries. Popular both here in the U.S. and the U.K. library patrons have a very accessible experience in Windows and iOS to log in to their library, browse, select and download audio and epub books. Overdrive can also let you borrow Kindle books which you can read in the Kindle app. In all cases, books expire automatically unless you renew them when the loan period is over.
I use Overdrive to consume a multitude of ebooks and audio books using my iPHONE, and sometimes Windows with a portable MP3 player.
When I logged in recently using Google Chrome on Windows, a pop-up appeared informing that Overdrive had a new app out called Libby. Libby was supposed to be friendlier, enabling one-tap borrowing. Right now you put a book on your shelf, then download it in Windows, but in iOS it's even easier, so I wasn't sure how much easier Libby could actually get. There was a video showing the app and lots of encouragement to download it for free.
I did, and when the app loaded it "played" a "secret message for screen reader users" which was heard through voiceover but would not appear if voiceover was off. Basically, the message apologized that Libby wasn't accessible, that the developers were aware of the issue, that the old Overdrive app would provide a better experience, and kindly requested users to accept their sincere regrets.
After the message, I continued, and it was indeed correct. The app is quite colorful with Libby being some sort of cartoon character "asking" you things. It showed a map and Libby asked you to point out your library on the map. I tried, even searching for my library, but the app is indeed not accessible for VoiceOver.
I wonder if Zoom users would fare better.
Original (accessible!) overdrive app
The overdrive app is also reasonably accessible on Kindle and Android though I prefer to use it on iOS.