The Tray Icon

When you run CastleBar and have the Always on Top option unchecked, CastleBar places an icon in the system tray.  This allows you to easily find CastleBar and bring it to the top of your active windows.  Simply left-click on the icon in the system tray and CastleBar brings itself to the top, so that you can see it.

 

 
Note that when the Always on Top option is checked, there is no icon in the system tray as CastleBar is always on top and visible.