View of the popSlate app on the iPhone screen.
Popslate: The Second Screen Experience
Another tech the popSlate depends on is the Lightening Connector of the iPhone. It “borrows power to change the screen, as well as enable all of the sensors and connectivity that the device has.”
There HAD to be a method!!!
Ref: popSlate Youtube Channel
E-Ink Case Turns the Back of Your Phone Into a Second Screen – Wired Magazine