Replaces the Google Calendar popup with something less intrusive
For people who hate how Google Calendar's alerts steal the focused tab and prevent you from clicking on anything until you've acknowledged the alert. This shows a nice, non-intrusive window, plays a sound (maximum of once per five minutes), and flashes an icon on the calendar tab. It stacks up multiple alerts, so you can dismiss them all at once or go through them one-by-one.
It's pretty much how things should have been to begin with.