Previous comment of no sound. I worked on this for a bit, and ended up with the following line as the command line: /home/myuser/timerstop. Timerstop being a small script that contains: (1)#bin/bash (2)# (3)timelimit -pq -t 5 xplayer /home/myuser/timerstop.ogg (4)# (5)xviewer /home/myuser/Desktop/Teststop.png (6)#. Numbers in parenthesis are the file line numbers and not part of the script. You have to install timelimit (sudo apt-install timelimit) The -t 5 option is for a 5 second application duration, that is, how long the application will stay open, so be sure to set it long enough for your sound byte to complete. Immediately following the sound I wanted a pop-up message on the screen, and it displays immediately after the sound plays. Not real pretty, but it works.
The timer counts down, but there is no sound that plays to let you know when the time is up. Shouldn't there at least be an option for a sound to play or am I missing something?