Show an icon into panel when UFW (Uncomplicated FireWall) is active/desactive. Tested with XFCE4 and OpenBox Desktop environment (Manjaro XFCE, Xubuntu and Mabox Linux)
Requisites: yad, ufw and gufw
pacman -S yad ufw gufw
or
apt-get install yad ufw gufw
then copy script gufw_icon.sh to some directory and add to application autostart menu of your linux distribution.
More info here: https://archived.forum.manjaro.org/t/how-to-add-an-ufw-status-icon-to-the-panel/38559