The iPad must be paired with a pen, otherwise it is for nothing. An iPad with a pen and an iPad without a pen are two species! Marginnote 3 requires a pen to draw a mind map
The marginnote 3 is such a software. The feeling of doing mind maps while reading a book is really great. All of my professional books are used to read. It is a sharp tool for paperless learning, allowing people to build knowledge connections from multiple dimensions, thereby enhancing the productivity of reading and learning.
Thus, the pen of iPad and The marginnote 3 are the most needed things for an iPad