Libby is the reading app from OverDrive, a company based in Cleveland, Ohio, that supplies digital books to libraries. Libby launched in 2017.
With a library card, users borrow ebooks, audiobooks and magazines from their local public library and read or listen in the app. Loans return themselves when they end, so there are no late fees. Popular titles can be placed on hold, and users can tag books and sync their place across devices. Many titles can also be sent to a Kindle in the US.
Libby is free. The books are paid for by the library, so a valid card from a library that uses OverDrive is all that is needed.