How to add touch buttons and input

This is the original code for Pc controls. How can I change it to android and use two touch buttons for left and right movement instead of normal touch, coz I tried it and it doesn't work for me.

Code (csharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class PlayerController : MonoBehaviour {
5.  
6.     public float sideSpeed;
7.     public float speed;
8.     public GUIText countText;
9.     public GUIText winText;
10.     public GUIText fallText;
11.     public Transform ground;
12.     private int coins;
13.  
14.     void Start ()
15.     {
16.         coins = 0;
17.         SetCountText ();
18.         winText.text = "";
19.     }
20.    
21.  
22.     void Update ()
23.     {
24.         if (coins>=10)
25.         {
26.             winText.text = "You Win!!!";
27.         }
28.         if(transform.position.y < ground.position.y)
29.         {
30.             fallText.text = "You're Down!!!";
31.         }
32.     }
33.  
34.     void SetCountText()
35.     {
36.         countText.text = "Coins:" + coins.ToString ();
37.     }
38.  
39.     void FixedUpdate()
40.     {
41.         float moveSideways = Input.GetAxis ("Horizontal");
42.         Vector3 movement = new Vector3 (moveSideways, 0.0f, 0.0f);
43.         rigidbody.AddForce (movement * sideSpeed * Time.deltaTime);
44.         transform.position += Vector3.forward * speed * Time.deltaTime;
45.     }
46.  
47.     void OnTriggerEnter(Collider other)
48.     {
49.         if(other.gameObject.tag=="coin")
50.         {
51.             other.gameObject.SetActive(false);
52.             coins = coins + 1;
53.             SetCountText();
54.         }
55.     }
56. }
57.