You need a multitouch-enabled device to get the most out of this demo.
Typical implementation of multitouch gestures for scale and rotation
often behave unexpectedly with more than two fingers.
This makes especially the two-handed transformation error-prone.
For instance, try to rotate by placing first your right hand and then the left.
As you can notice, only the first two fingers affect the scale and rotation.
This demo was made with Hammer.js touch gesture library.