I am thankful always xodo develope team.

There is 'marginnote3' app in iPad.
Of course, the xodo app is much more useful that to read and write pdf files.

However, 'marginnote3' has a powerful feature that xodo does not have.
It is a function called "mind map"

Divide the tablet screen in half,
and display the "MIND MAP" on the left / the PDF file on the right side.

Users can select the contents (or images) of the right PDF and paste it into the left MIND MAP.

Also, when users select the contents of the left MIND MAP, it shows the corresponding page of the right PDF (just like a bookmark).

This powerful feature helps users easily identify and understand complex & massive contents.

It will be very useful for business and college students who need to review vast amounts of documents,
It will also be of great help to users who want to read novels and other kinds of books and make "reading notes".

Add a website for 'marginnote 3' app developer, as it may be a reference
https://www.marginnote.com

I wish development and prosperity of the xodo development team.