I am both skeptical and interested:
- Looks like you turn the knob to set your page
- This, and your book title, appear to be the only input data to the system (no other sensors)
- Does this mean they aim to have a database of the text of every edition of every book, indexed by page?
If they can pull it off I think it could be useful, but I think they will need to compromise on quality if they hit copyright issues.