main.js

if (window.DeviceMotionEvent) {
  window.addEventListener('devicemotion', deviceMotionHandler, false);
} else {
  document.getElementById("warning").innerHTML = "Not supported."
}


function deviceMotionHandler(eventData) {
  // Grab the acceleration from the results
  var acceleration = eventData.acceleration;
  var trimmedaccel = acceleration.x.toPrecision(2)
  
  switch (trimmedaccel >= 0) {
  	case true:
  		$("body").addClass('up');
  		$("body").removeClass('down');
  	break;
  	case false:
  		$("body").addClass('down');
  		$("body").removeClass('up');
  	break;
  }

}