KDocker
Lets you dock any application into the system tray
KDocker will help you dock any application in the system tray. This means you can dock openoffice, firefox, thunderbolt, eclipse, anything! Just point and click. Works for both KDE and GNOME (In fact it should work for most modern window managers that support NET WM Specification. I believe it works for XFCE, for instance)
All you need to do is start KDocker and select an application using the mouse and lo! the application gets docked into the system tray. The application can also be made to disappear from the task bar.
KDocker will help you dock any application into the system tray. This means you can dock openoffice, xmms, firefox, thunderbird, anything! Just point and click. Works for all NET WM compliant window managers - that includes KDE, GNOME, Xfce, Fluxbox and many more.
How to install KDocker in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install kdocker in Ubuntu
sudo apt install kdocker