Librera only reads local files, so you need to already have your books. It has a few reading modes, does text to speech to turn regular books into audiobooks, sheet music mode to flip pages for you, and some other fancy stuff I haven’t tried.
I used to use MoonReader, but this is FOSS so I switched over. If you get it from F-droid, you get the pro version and it also has no Google Play services.
If you have a source of book files (PDF, epub, Kindle, cbz, etc) such as Project Gutenberg or another alternative repository of books, you are set. The archive source I use has the things I look for: older fiction, sheet music, programming books.