Opus can add an icon to the taskbar notification area (also called the "tray" or "systray" icon), and you can configure what happens when you double-click it. You can also edit the context menu that's shown when you right-click it.
Note that Windows will probably hide the icon and move it to the overflow area by default. If you want the icon to always be visible (which makes the double-click options on this page more useful) you will need to tell Windows to show it all the time.