On PC you can find the icon for ProjectCoordinator Desktop down to the right if you click on the up-arrow (Notification area). Click on the icon to open the main window for ProjectCoordinator Desktop again. NOTE: You can change settings for that under "Customize" if you want the icon to show all the time or not. Change from "Only show notifications" to "Show icon and notifications" if you want the icon to be shown all the time.
On Mac you always got the icon down in the "Dock" (if you haven't change where it will show). If you click on the icon the main window for ProjectCoordinator will show.