Would improve the quality of my sketches dramatically.
I find an option to see/hide faint sqared lines most useful
A merge function would be extremely nice since professors frequently post chunks of chapters every week or update parts of their lecture notes as they go
Honestly, with the page last viewed menu as well as a direct sync to the file storage of my (dropbox) cloud storage I would be totally happy and organized
Just draw a line with the geometric tool and delete small sections with the eraser! It' super fast :)