Copy the "TestCustomViewboxes" folder to the Unity3D project into Assets folder. Please be sure you have NoesisGUI installed before doing this. Then you could open test scenes and play them.

There are two example scenes - TestWindow and TestHUD:

• TestWindow example uses a ScreenViewbox - it simple scale its content proportionally to the screen size.
• TestHUD example uses several ScreenAutoViewbox'es. It's a more complicated control: it scale its content proportionally to the screen size and with accordance to its multiplier factor. It will also properly align control according to Horizontal/Vertical alignment and takes margins into account.

Forums topic - http://www.noesisengine.com/forums/viewtopic.php?f=3&t=822&p=4550#p4550