gistfile1.txt

        protected static void AddParallaxEffect(UIView back)
        {
            //var frame = back.Frame;
            //back.Superview.RemoveConstraints(back.Superview.Constraints.Where(c => c.FirstItem == back).ToArray());
            //back.Frame = frame;

            var keypathx = "constraints[0].constant";
            var keypathy = "constraints[1].constant";

            var xMotionEffect = new UIInterpolatingMotionEffect(keypathx, UIInterpolatingMotionEffectType.TiltAlongHorizontalAxis)
            {
                MinimumRelativeValue = new NSNumber(-10), 
                MaximumRelativeValue = new NSNumber(10)
              };

            var yMotionEffect = new UIInterpolatingMotionEffect(keypathy, UIInterpolatingMotionEffectType.TiltAlongVerticalAxis)
            {
                MinimumRelativeValue = new NSNumber(-10), 
                MaximumRelativeValue = new NSNumber(10)
            };

            back.Superview.AddMotionEffect(new UIMotionEffectGroup {MotionEffects = new[] {xMotionEffect, yMotionEffect}});
        }