This will make it work.. Rated 4 out of 5 stars
Install this add-on: https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/?src=collection&collection_id=4b31420e-fedd-49e8-ae66-6df226d20120
And then the clipmarks one.
But would also like to see it updated, I certainly prefer this one above the amplify version! If it's updated it will receive a 5 star rating :P