Don't get me wrong! Rated 3 out of 5 stars
Thank you for your prompt reply and info., please don't get it wrong, I think it's a wonderful add-on, but it just didn't work for me, thus the 1 star, and yes I am using the latest Ff 16.0.1.This review is for a previous version of the add-on (2.1.1-signed). This user has other reviews of this add-on.
Would you please give more information about what do you mean by "the app did not work for you"? i.e., did it open when you click the browser icon, if opened, when you click a symbol button, a text box should open to show that symbol, you then click Ctrl+C to copy then Ctrl+V to paste. You can try the service at http://www.i2symbol.com to see what the app action should be.