I am using the example provided by MDN here but touch.rotationAngle is always 0 and touch.radiusY alway equals touch.radiusX.
MDN says "This attribute is not widely implemented", but knowing for sure would be helpful.
So do touch.rotationAngle and touch.radiusY work on mobile (iOS/firefox and iOS/Chrome)?
In the browser compatibility section, iOS/Firefox and iOS/Chrome are not listed as supported platforms. Therefore, it looks like these browsers on iOS don't support the attribute.