I'm looking for a simple countdown timer application, something similar to timer-applet, which appears to be deprecated. (It's in the repositories but when I tried to install it there were dependency issues with gnome-audio and it hosed my system.)
My ideal app would have the following features:
is lightweight and fast (starts up fast and doesn't use a lot of system resources)
has functionality for user-defined presets for commonly used times (like for using the 10+2 work method)
plays a sound and displays a notification when the time set is reached.
is a native GNOME app & not a webapp
is an indicator applet
Note: I am looking for a countdown timer app, not a timetracking app.
alarm-clock-applet might be what you are looking for, you can save pre-sets for either alarms (specific time) or countdown timers. Two advantages over timer-applet is that several timers can run at the same time, and you can set a custom snooze time.
It's in the Software Center.
I've also had trouble with timers. What I settled on, finally, is the Tomboy Reminder plugin - I work in 20 minute bursts. So I just set a reminder in a Tomboy note for 20 minutes from now. When the time has elapsed, the note appears on top of everything else, impossible to ignore. If I decide I need more time, I just type in a new time for the reminder. (I do realise you were asking for a sound, and a countdown in the panel, but because I was looking for the same thing and found this to be an excellent alternative solution, I thought you might find it helpful.)
gnome-shell-pomodoro looks like a good app for having a visual countdown in the menu bar. It's designed around a repeating countdown of a set interval followed by short breaks and then a long break after a certain multiple. A good option if that's why you want it (answer left for those searching for this)