When a reader has a question on a certain page of the book, he first identifies the book (by entering the ISBN, or use barcode scanner inside the app), then he takes a photo of the page, taps the location on the photo to enter his question. After the reader submits his question, the author or expert will see the question and can answer the question right at the spot. This helps the reader get authentic answer he wants while saving his time to search online, and also helps the author to better disseminate knowledge without misunderstanding. The Q&A can be viewed by other readers.