Dennis den Ouden – Van der Horst created a new extension, based on the work of Max Ramgraber: an interactive graph of book content! This allows you to add a clickable graph of internal references and the table of content, providing your reader with an interesting way to navigate your book’s content!
The graph is created automatically based on existing internal reference, but it highly customatisable from the table of content file too! Check out an example of this graph in this Linear Algebra book.
The repository of the extension can be found here, while it’s added to the manual too