Rated 5 out of 5 stars
I use this only for the clock, but it keeps on switching back to the timer-icon everytime I restart firefox. Other than that, great and simple add-on that does the job.
Edit: I'm an idiot and the developer answered quickly. Fantastic addon!
Just set an option...
In Options->Miscellaneous->Startup Options, select Start clock. Hope you come back to read this. Thats why if you have a question/problem, its always best to send me an email!