Update:
I have been using the app for a very long time and I must say that this app is simply amazing and I don't understand how this app isn't at the top of the charts for what it does.
Simple example: you can save a webpage as a pdf (to do this on an iPad is hard enough)
And you can actually edit, highlight and draw with a pen and do pretty much anything you want with the webpage.
Go and try to do what this app does on Microsoft One Note or any other editor. No chance.
I just want to say thank you for the people whom put their time into this brilliant app!
I have been using this app for more than 6 month now. It has never crashed, never lost any data, it is ideal for reading and taking notes, highlighting, underlining, typing on the pdf file itself with ease and exporting the edited document very easily. ( it has many many more details which you can read about)
This app is a must have and have actually helped me to achieve more efficient reading and note-taking.