Libby is my very most favorite app because free books
With the help of my public library, books magically appear on my eReader.
Libby is the app my local library uses to make it's ebook and audiobooks collections easily available to the public. Discovering it has improved my life.
I have long since accepted that paper books are a quaint and funny affectation, like organized religious or dial-up modems, that will someday go away. I have a HUGE collection of physical books but try to limit purchases to books that truly benefit from being in physical form: magic and cooking.
Everything else takes up space.
The bulk of what I read is science fiction and other storytelling. I need a constant stream of stories, or I won't be able to sleep. The Libby app is the first place I check to see if I new book I've heard of is available.
Libby indexes whatever my library, or libraries if you have cards at more than one participating organization, has to offer via the internets. Audiobooks, which are not really my bag, and ebooks are pretty easily searchable by the various criteria you'd expect. If what you desire is immediately available you can read or listen via the Libby app, or send the media to other players. I have Libby connected to my Kindle, and a simple click or two sends books directly to it.
The hold system is a huge surprise benefit, imho!
My library loans books for 21 days and if someone is waiting for the book I feel like a real heel holding on to it. Yes, the system tells you. I find this, and the notifications that a book I'm holding is available, to be highly motivating! It has also helped me learn to give up on some books I start and do not like. That is a bit of a relief.
If you have a library card, give Libby a try. If your library doesn't support Libby, perhaps they have another solution.