I have used it for years. And I was happy with it, I used it extensively all day long. But when it was last updated two years ago, this previously excellent extension suddenly lost the ability to keep personal settings... You have to reload them in memory from your backup every new Firefox session! An extremely annoying and time-consuming process. As a result, the extension loses most of its interest, and the developer seems to have completely abandoned it. About six months ago I switched to another extension, Swift Selection Search, which does exactly the same job (minus the custom sub-menus) but works perfectly and with the same possibility to save personal settings... but which doesn't require to reload them manually at each Firefox session. A dream! This Selection Context Search extension lost all its interest when it was updated two years ago. Better to switch to Swift Selection Search.