I read the OP's post and thought I'd try it out.
This is great, similar to AirManager & Knobster for $17.00 :)
I did a screen shot of the Cessna 172 main gauges and added transparent buttons to them.
Now I can control the knobs that are associated with the gauges by a simple touch.
I have touch to move the knob 1 increment, and a hold state for moving fast.
I just picked up the pro version today, so far I like this.
Thanks
Here's where the buttons will live....so far
I'll add the pages for other controls and views after. This is sweet https://gyazo.com/9ef3bffcda6ffdb064892bed5d8829a4