code: function showTouches(ev) {
          var touch, i, el, styles;
  
          // first all visible touches
          for(i = 0; i < ev.touches.length; i++) {
              touch = ev.touches[i];
              el = touchElements[touch.identifier];
              if(!el) {
                  el = touchElements[touch.identifier] = document.createElement("div");
                  document.body.appendChild(el);
              }
  
              styles = TouchEmulator.template(touch);
              for(var prop in styles) {
                  el.style[prop] = styles[prop];
              }
          }
  
          // remove all ended touches
          if(ev.type == 'touchend' || ev.type == 'touchcancel') {
              for(i = 0; i < ev.changedTouches.length; i++) {
                  touch = ev.changedTouches[i];
                  el = touchElements[touch.identifier];
                  if(el) {
                      el.parentNode.removeChild(el);
                      delete touchElements[touch.identifier];
                  }
              }
          }
      }
docs: show the touchpoints on the screen