Works really well, but still has the problem the similar google extension has; it can't handle plurals. If I double click on "extensions" it will spit out "plural form of extension". This is not helpful at all, since no one in the history of the world looks up an unknown plural word expecting this. If this could be fixed, I would pay money for it. Otherwise it's fantastic, and it's great that it saves all your looked up words conveniently to test yourself on.
