Have you guys heard about Farfaria? They have over 800 books (included sing-a-longs) for various ages. You get to choose one free book everyday.

If you subscribe with them for $5 per month (or $40 per year), you get unlimited access to all of their books.

We're Luddites when it comes to kids and tech, but this has me rethinking our decision to only read LO physical books.