GUI Resizing.
 

Currently the resizing of GUI windows is a feature that works, but unless you just randomly drag a direction there is no real indication that you can resize the windows.

I don't know about anyone else, but I find this pretty annoying personally and I think it'd feel better if the mouse showed that you could resize the window, and the direction based on the position your cursor is in; you know, like all other software has.

You mean change the system cursor to indicate the resizing behaviour?

Yup.

Also, apply the same concept to Mac version of Graal -- there is nothing to drag, and it is hard to find anything to drag to resize it.