I read books on the Apple Books app, and whenever I have a question, I find myself switching to ChatGPT or Claude, and discussing the contents of the book with it. But it would not have access to the book, and it was also a clunky way to clarify and understand the book as I'm no longer looking at the contents of the book but just responding on a chat interface.
I felt there had to be a better way - it was hard to imagine how Apple Books still looked the same as it did 5 years ago. So Simple Reader was an attempt to bring Apple Books into 2025.
You have the same clean, familiar Books-like interface to read the book, but in case you'd have a question, want to clarify a snippet of the book, you select it and you can ask a question inline. No separate chat interface, just discussing right where you are.
And in case you wanted to have a longer discussion about a chapter or the book as a whole, you could just expand it to a sidebar and discuss the book while reading.
An extension to this was a voice-to-voice experience which required no typing, you discuss the book hands-free.
Now the next time I was reading an Iain Banks book and the paragraph was too dense for me, I didn't have to switch tabs.