Here’s another suggestion for SketchUp Mobile products: SketchUp Mobile NAV
I was looking at this: SketchUp Skill Builder: 3D Mouse - YouTube
So I thought: why don’t you create an iPad/iPhone companion app that works as Navigation tool for SketchUp Desktop?
Vectorworks has something like this and works pretty well.
How would it work ? As a trackpad ?
I was thinking more about a “camera control” that works with the mouse. You should use the mouse with the right hand (select tool, point, click) and the left hand on the touch screen of the iPad or iPhone that controls camera (pan, moving around, zoom) watch the video attached to better understand what I’m referring to 
I did watch the video.
It doesn’t make economic sense to me to use an expensive communications device (and put that much wear on it, ) when a much more affordable device like trackpads, touchpads, and 3D contollers are available.
If you have a mouse, with a middle button, you have instant orbit; and pan or zoom in it’s right-click context menu,( ie, MMB+RMB.)
But yea, let’s say your at the airport, your flight is delayed, and you forgot your mouse. Ok, I can see using the phone as a backup.