I’m going to put a scroll bar on the back of the phone.

There must be a way for a back touch pad. It will allow for double edged smart devices. You can use the back of the phone with your pointer finger to scroll and click.

I imagine it would be like a touch pad (laptop-ish), so perhaps some navigation as well. Paired with a touchscreen front, it may work out to mostly use it for scrolling.

I think you could select an app on the front, and go through the menu on the back, and click with either side. It kind of flows through the touchscreen click and into the scroll bar, and bounces back to the touchscreen.

It frees the screen from fingers for some interactions.

WT