Gyroscope Head Tracking for Unity

HeadTracker.cs

using UnityEngine;
using System.Collections;

// Activate head tracking using the gyroscope
// The script must be linked to the main camera
public class HeadTracking : MonoBehaviour
{
  // The initials orientation
  private int initialOrientationX;
  private int initialOrientationY;
  private int initialOrientationZ;

  // Initialization	
  void Start ()
  {
    // Activate the gyroscope
    Input.gyro.enabled = true;
    Input.gyro.updateInterval = 0.01f;
    
    // Save the firsts values
    initialOrientationX = (int)Input.gyro.rotationRateUnbiased.x;
    initialOrientationY = (int)Input.gyro.rotationRateUnbiased.y;
    initialOrientationZ = (int)-Input.gyro.rotationRateUnbiased.z;
  }
  
  // Update is called once per frame
  void Update ()
  {
  	transform.Rotate (initialOrientationX -Input.gyro.rotationRateUnbiased.x, initialOrientationY -Input.gyro.rotationRateUnbiased.y, initialOrientationZ + Input.gyro.rotationRateUnbiased.z);
  }
}