Open/Start Device Native Camera in Unity3D app using C# script, Without 3rd Party Plugins

Recently I started learning Unity3D with iOS and Android Platforms. and gone through bunch of resources to get basics of Unity3D and scripting language.
Example : Unity3D Beginner Scripting

but still I am not able to start/open iPhone/Android device camera using C# script in my Unity3D application. everytime I found regarding Game object camera not device camera.

Can anyone please guide me in this, what is the Class name for Device Camera or How to initiate.

my C# script file is (OpenCamera.cs) :

using UnityEngine;
using System.Collections;

public class OpenCamera : MonoBehaviour {

	// Use this for initialization
	void Start () 
	{
		Debug.Log ("Start function get called");
		//I want to start camera here
	}
	
	// Update is called once per frame
	void Update () {
	
	}
}

After some more digging on Google and Official docs. I got solution which I am going to share with you , It help someone … someday…

1.Create New Project.

2.Select Main Camera in GameObject and change Transform via Inspector

Position X= -90 Y=785 Z=0
Rotation X=90 Y=90 Z=0
Scale X=1 Y=1 Z=1
[27875-screen+shot+2014-06-17+at+5.26.32+pm.png|27875]

3.Now go to GameObject — > Create Other — > Plane.

4.Select Main Camera in GameObject and

4.1change Transform via Inspector

Position X=0 Y=0 Z=0
Rotation X=0 Y=0 Z=0
Scale X=100 Y=100 Z=100

4.2change Tag=Player

Now create a c# script with name “CameraController” and replace the code with below one

using UnityEngine;
using System.Collections;

public class CameraController : MonoBehaviour
{
		public WebCamTexture mCamera = null;
		public GameObject plane;

		// Use this for initialization
		void Start ()
		{
				Debug.Log ("Script has been started");
				plane = GameObject.FindWithTag ("Player");
		
				mCamera = new WebCamTexture ();
				plane.renderer.material.mainTexture = mCamera;
				mCamera.Play ();
		
		}
	
		// Update is called once per frame
		void Update ()
		{
	
		}
}

5.Finally save and Drag this Script file onto “Plane” GameObject

Note - you may see preview rotated in Unity Game view but on RealDevice it works well.
tested on iPhone5 and Android - Nexus 5.

Here is the snap shot how it comes if you change rotation angle to 180:
[27879-screen+shot+2014-06-17+at+2.18.252+pm.jpg|27879]

thanks!
In Unity 5, change the line:

plane.renderer.material.mainTexture = mCamera;

replace for:

plane.GetComponent<Renderer>().material.mainTexture = mCamera;

Hello how switch back camera on front camera? help me pls