GNOME Shell extension providing a countdown timer in the top panel
Installing this package adds a timer application to the GNOME Shell top panel. With it you can start a timer of any duration and when elapsed, you'll get a notification. You can also preconfigure various durations to avoid having to retype them.
It's a natural replacement of the "timer applet" for GNOME 2 (or 3 in fallback mode).
Users of the Pomodoro method will find this extension very useful.