Rated 2 out of 5 stars

1. sound notification does not work (linux)
2. always opens a new tab, not transferred to the previously open

p.s. v0.2.0 "No sound alert in Linux (OS==Linux)". Going back to the "Gmail Watcher" :(

This review is for a previous version of the add-on (0.1.9.1-signed). 

Both are now fixed in 0.2.0 version:
https://github.com/inbasic/ignotifier/issues/25
https://github.com/inbasic/ignotifier/issues/26