I hope this works on your end. This is the whole reason I thought I was having problems with full screen. Without the extra parameter behind the Touch.Y the controls were off. With it, the program locks. I just didn't realize what was happening at first.
The fps counter is just in there to show that the preview stops responding if the screen is clicked or touched.
Construct 2 r84
Mobile Safari 5.1
Firefox reports the following error
Error: layer.canvasToLayerY is not a function
Source File: localhost/Touch_plugin.js