if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved) {

            // Get movement of the finger since last frame

            Vector2 touchDeltaPosition = Input.GetTouch(0).deltaPosition;

​

            // Move object across XY plane

            transform.Translate(-touchDeltaPosition.x * speed, -touchDeltaPosition.y * speed, 0);

        }