How can i translate mesh vertex point used touch on Android

How can i translate mesh vertex point used touch on Android (It should stay on when I stop touch).

I want to stretch and shrink the mesh object same as skin stretch and shrink

how Should i solve problem?

MeshScrip Code;

using UnityEngine; using System.Collections;

public class BuildMesh : MonoBehaviour{

 public Vector3[] vertices = new Vector3[4];

 // Use this for initialization
 void Start () {
     MeshFilter mf = GetComponent<MeshFilter>();
     Mesh mesh = mf.mesh;

     //Vertices 

     vertices[0] = new Vector3(0,0,0);
     vertices[1] = new Vector3(10,0,0);
     vertices[2] = new Vector3(0,10,0);
     vertices[3] = new Vector3(10,10,0);

     //indexs

     int[] triangles = new int[6]{
         0,2,1,
         1,2,3
     };

     Vector2[] uv = new Vector2[4]{
         new Vector2(0, 0),
         new Vector2(1, 0),
         new Vector2(0, 1),
         new Vector2(1, 1)
     };
     
     mesh.Clear();
     mesh.vertices = vertices;
     mesh.triangles = triangles;
     mesh.uv = uv;
     mesh.RecalculateNormals();
 }    

}