Useful, but there are too many cases where are page just happens to load too slowly for the extension's taste so it pops up offering to use the service, blocking the entire page.

It would be nice if it would really only show up when the page is 404 and not because the page is coincidentally loading slowly.

A nice extension. Generally works but occasionally has hiccups.

That said, updating to the newest version needlessly cluttered up my context menu with duplicates of the stuff available through the browser action (that I currently have to resort to userChrome.css to remove) and non-optionally added a requirement for notification privileges with no option to turn off whatever annoying popup it's planning to display.

I'm giving it a 3 out of 5 for those warts.

Please don't change the URL. Please. That's horrible UX, makes me want to disable the extension right away.