Iphone to Touch on TV

Hello! Looking to design hardware with software that always you to plug in both a touchscreen overlay such as a Green Touch overlay to a TV to make a small Iphone or Ipad into a 70 inch TV. The Iphone or Ipad will mirror image on the TV. The Touch Over lay would plug into a device that allows you to connect to bluetooth on the Iphone or Ipad so the giant TV becomes the IPad or Iphone.

– This company does it: https://crunchytech.com/products/padzilla-giant-iphone-giant-ipad-2/

-This guy also designs it see youtube video: https://youtu.be/f6YDjlGJF5Q

Thank you,