Creating pseudo-modal App Designer apps that return outputs

"inputdlg" was really handy for creating a dialog that would pause your code, get user inputs, and then continue executing based on those inputs.

Since there isn't a way to accomplish this workflow within the App Designer framework yet, I built this workaround to help me accomplish what I was looking for.

This utility allows you to accomplish 2 primary workflows:
1) call your dialog app from code and have it block MATLAB code execution until the user finishes with the dialog
2) call your dialog app from within another app (the calling app) and block user input on the calling app until the user finishes with the dialog

Benefits:
-- Allows you to take advantage of the great App Designer editing features
-- Allows you to build more customizable input dialogs compared to inputdlg
-- Will automatically return all public properties and editable values in UI controls
-- At its most basic level, it requires four (4) simple 1-line code changes to your App Designer app to enable this calling method

Note:
This code requires R2018a+.