Notification sounds are not working. It can be difficult to specify an exact time to count down, but the lack of notification is what really is annoying.

Display only shows timer counting down or gives alarm sound when the extention window is active now or if my firefox just started up, it lasts ~30s before freezing. Last update was 3 years ago and another timer app's countdown works fine so it could be that it's just too old for my firefox :( FF ver.106.0.2 (64-bit), windows