Request - Control focus with smartphone

[hugomfranca]

This is an idea for a very useful app running on android which allows focus control of fly by wire lenses through the smartphone. The UI works by turning a virtual knob with the finger. But we can go a step further and a simple accessory in the shape of a wheel could attach to the smartphone with a small suction cup and rotate the digital knob. The idea is to emulate a remote follow focus, very useful for working with focus pullers, working with a remote monitor, and specially for gimbal work. The app could also toggle between focus and zooming. Take a look at the attached image.

I can help with the design and manufacture of this accessory. Looking for programmers who want to help out developing this.
I have no programming skills at all, just the idea, any help i can give let me know.