The Conforms to Screen behavior will create boundaries around your visible screen space so your specified object can't go past them.
Note that scenery objects will not work with the behavior..
This behavior will Trigger an event immediately when it executes.
This is the object that can't leave the boundaries of your visible screen. By default the current object is selected. You can select any object in your scene by tapping the graphic.
This outputs the Object ID.
If you want to create a game like pong, you can use this behavior to make sure the ball stays within the visible screen space.