A page counter would be fine. As of now the only way to know where exactly you are on a document is to open the thumbnail feature. If the page number were displayed (maybe as an in/out option) it would save us a good deal of time.

Currently all folders appear as blue. It would be great to organise folders with different colours (e.g biology- green and maths - red)

This option to have lasso tool to be able to copy, paste, and move existing text, images, graphs, any visuals that are important would be simply amazing.

In the tool bar there are only 3 available colours to select from
Adding more colours to the toolbar would make more efficient and fluent writing

Ability for application to allow GIF images and to show animations.

I would love it if there was a way to access notebooks online in a way that we could edit the organization of the notebooks. This could be in the form of a website where you can log in to access your notebooks, or maybe making a downloadable app/program for Windows.

I would like more options on what you can do with the text box. Such as:

1) ability to have two different writing styles in the same text box (red and black, bold and regular)
2) An indent button
3) maybe even a whole different text box for bullet points, lists, and things of that sort

Actual the size of the paper is fixed.
But nevertheless that I use A0 I am limited during Brainstorming and other creative workshops. Therefore I must use another tool (Zoomnotes). But this is not helpful at all to switch from tool to tool.
Is there a chance in the near future to implement a more to enlarge the size of the paper endless?

The GUI has a lot of "lost space" - especially in landscape mode. Would be great to have the full screen for a sheet of paper with a rearrangeable toolbar. Would be extremely helpful for iPads with 9.7 or the upcoming 10.5".

Add divider tabs into notebooks to make it look like a loose leaf binder

A separate button next to the “pens” for typewriting. This would entail being able to type normally wherever we tap on the page to create an insertion point. This would also contemplate minimal text styling; bold, italic, underline, several colours and the ability to change font and/or font size for any given part of the text.

Integration with onenote

As teachers, we use this to take pictures of lessons on which we are working, allowing students to highlight and write on the photos. Students also create short presentations of their work, which we record. It would be awesome to be able to insert video into Goodnotes!

I typically need to work on the same document in multiple devices. For example, i may annotate a pdf at home using my iPad but at work I may need to read the annotated pdf in my laptop. Would be great to have full synch using iCloud Dropbox or similar services

You definitely have to include the Dropbox sync function as realized in goodreader. this would be essential!
And I'm convinced a bunch of people will be willing to pay more for your app