Here are some ideas about new features for the 3D Navigation addon:
I think it might be interesting (and useful) to add extra views. At first, I thought of adding all other buttons next to the Front, Back, Left, Right, Top, Bottom buttons:
... but that would clutter the panel. Too many buttons might confuse the user.
But a simple dropdown button could gather them all without filling the whole interface:
Also, I think it would be useful to be able to save views in bookmarks: