If you are using Unity version of Ubuntu and you want the you favorite programe (eg. Skype) run on your systems/notification tray, try the folowing method. It’s pretty simple and safe.

Open a command prompt and run the following command.

gsettings get com.canonical.Unity.Panel systray-whitelist

You may get a following list of application already running in the system/notification tray.

[‘JavaEmbeddedFrame’, ‘scp-dbus-service’]

With the above result you can enter the following command apppending the application you require in the system/notifction tray as follows,

gsettings set com.canonical.Unity.Panel systray-whitelist “[‘JavaEmbeddedFrame’, ‘Skype’, ‘scp-dbus-service’]”

That’s it… All you require a log off the current session and log back in.