As part of the x-callback-url support, external apps can lookup scriptures in the Equipd Bible and pass in arguments in the url that enable a special button to switch back to the referring app. The idea is to add the ability to use the "2-finger" tap gesture to switch back to the referring app. That way the user does not need to hit the button at the bottom of the screen - they can optionally tap with two fingers anywhere on the screen, which is a lot more efficient.
