Gmail calendar event notification Rated 4 out of 5 stars

I was glad to see this notification add-on in firefox. In chrome on Ubuntu, the gmail calendar event notification stays up until acknowledged. That is good because I will not miss the calendar
invite if i'm not looking at the screen at the time of the notification. Could this feature be added for calendar event notifications? Thanks.

This review is for a previous version of the add-on (1.0.3).