A professional meteorological mapping and modelling tool we use at work has exactly this: A simple "declutter" slider. And it is easily one of its most impress

A professional meteorological mapping and modelling tool we use at work has exactly this: A simple "declutter" slider. And it is easily one of its most impressive features - so incredibly simple (esp. compared to all the other bells and whistles it offers) and yet constantly proving its usefulness in everyday use. Gmaps & Co. have become even more tiresome to use since I actually have experienced how much more comfortable it could be.