Rebind claims to be a "mindfulness app for deep reading, guided by the world's most interesting people. Rebind challenges you to engage with a book in a whole new way."
Huh?
Yeah, so it appears to be a site that at the moment has a limited library of titles, each "hosted" by experts on that title. While you read the ebook, their notes and commentary are available. In addition to just annotation, there's an AI interface that connects you with the notes of that expert, so you can, at any time, ask specific questions and have them answered by the AI which uses the well of information that the expert provided.
It's certainly an interesting idea, and if I had an extra $120 lying around I'd try the annual membership. I'll check back in the future to see how the library expands. It's certainly an interesting approach to AI.
Like with Audible, the first month is free. Switching from Audible? First three credits are free by using the code SWITCH. Yes, they have far fewer books than Audible, but the selection is pretty good overall and the sale books have some great titles.