I agree about the comments on appDesigner
After a lot of work, and bending one's foot round one's ear, one can write a GUI that has most of the functionality written in Visual stdio or Fortran. But it seems counterintuitive and everything that one would like to do, and would think is being easy, is "not supported".
There is no doubt in my mind that appDesigner needs more functionality if one is going to write an artistic, commercially useful, GUI that is not simply knobs and sliders. Apart from the difficulty in getting the mouse position, one desperately needs to be able to draw on the uppermost layer of the GUI, not in a plot, but in the container itself.
I may be being unfair, and this may be possible, but finding one's way around Matlab documentation, apart from the most basic aspects, is really difficult.