The image below is a sample of what the plug-in will do for you. 

Select Magic Wand tool and mark background. When you release mouse button, the background will be removed. In order to mark erased object, use mouse right-click. 

You can see that background is not deleted properly. Increase Strength parameter in order to increase degree of erasing. Set Contract parameter to 1 in order to avoid high-contract border around dog.