How do I create a pdf book app?

[TIMAI2]

You could use this:

[Free] ViewPDF - a simple pdf viewer for local files & ViewBigPDF

1. Introduction I was doing some work with @Juan_Antonio's KIO4_PDF extension and realised that it was possible to view ANY pdf available on the device (within reason, depending on location, Android version / API). I came up with some blocks to make it possible to view an entire pdf in a webviewer. (There are already straightforward methods for viewing pdfs locally and from online resources) In discussion with Juan, and with his help and code, I then developed this extension which would do the…

or this

App Inventor Extensions: Pdf | Pura Vida Apps

to view local pdf files