MUST HAVE very useful script to rapid switch to the viewport closest to viewpoint angle in perspective/orthogonal view of object you are modelling. The analog of behavior of constrain angle snap in ZBrush (activated by holding shift key).
Good replacement for internal switching between viewports hot keys (T/L/B/R/V), allowing you to rapidly switch to the top, bottom or side views while modeling. Instead of 5-6 keys, now you will have only one, that is more sense and intuitive.
new in v1.10: press hotkey again to switch back to the previous perspective view