Somethings you should know Rated 1 out of 5 stars
First off, this add-on doesn't work if coupled with some other add-ons such as Snap Links.
Second, if you close Firefox without turning it off, it basically just shuts off cookies and history and it gets really annoying having to turn on cookies and history and remember all the sites you actually wanted in the address bar for about the twentieth time.
Third, if you DO turn it off before shutting down, IT DOESN'T WORK. IE: You turn it off, then shut down, guess what's waiting for you in your history? EVERYTHING YOU DIDN'T WANT TO FIND THERE, THAT'S WHAT.
So be aware that these are things you may (and probably will) run into after installing it.