Skip it. Rated 1 out of 5 stars
I really wanted this to be great. Sorry – epic fail. The toolbar icon repeatedly vanished when the browser was relaunched, making the add-on useless. Truth: I have tried and/or kept hundreds of add-ons over the years, and this is a totally new and unwelcome trick!!
Also: the sound alert is pathetically quiet, Again: functionally useless. And there's no way for the user to alter or replace that sound.
So I switched to the regular (not restartless) add-on of similar title: that works just fine.