Turn clear glass into frosty state using electricity is not a new technology.  Saint Gobain Glass of France invented the product and Sage Glass of US has come up with their own version.  Both products are laminated glass units and are used as component of framed window unit. 

The break through of EG Shade is the technology of producing the Clear to Frost switching mechanism on a thin plastic film.  The thin film can be installed over existing window glass by way of static adhesion and it can be taken down and re-used.  This breakthrough vastly expands use of an established technology which was otherwise only used in new construction.

Use of switchable glass -

Window Covering

Rear Projection Screen