Android Adding extra item on listview

package org.example.veniew;
import greendroid.widget.ActionBarItem;
import greendroid.app.GDListActivity;
import greendroid.graphics.drawable.ActionBarDrawable;
import greendroid.widget.NormalActionBarItem;
import greendroid.widget.ActionBarItem.Type;

import java.util.ArrayList;
import java.util.HashMap;

import org.example.veniew.library.JSONParserList;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;

public class CategoryActivity extends GDListActivity{

    //URL request
    private static String url = "http://10.0.2.2/veniew/catelist.php/";

    // JSON Node names
     private static final String TAG_CATELIST = "catelist";
     private static final String TAG_CATEGORIES = "categories";

     JSONArray catelist = null;

     @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // Hashmap for ListView
            ArrayList<HashMap<String, String>> cateList = new ArrayList<HashMap<String, String>>();

            // Creating JSON Parser instance
            JSONParserList jParser = new JSONParserList();

            // getting JSON string from URL
            JSONObject json = jParser.getJSONFromUrl(url);

            try {
                // Getting Array of Categories
                catelist = json.getJSONArray(TAG_CATELIST);

                // looping through All Categories
                for(int i = 0; i < catelist.length(); i++){
                    JSONObject c = catelist.getJSONObject(i);

                 // Storing each json item in variable
                    String categories = c.getString(TAG_CATEGORIES);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_CATEGORIES, categories);

                    cateList.add(map);
                }

            } catch (JSONException e) {
                e.printStackTrace();
            }

            /**
             * Updating parsed JSON data into ListView
             * */

            ListAdapter adapter = new SimpleAdapter(this, cateList,
                    R.layout.list_cate,
                    new String[] {TAG_CATEGORIES }, new int[] {
                            R.id.categories});

            setListAdapter(adapter);

          //to add more new items in list
            adapter.add(new HashMap<String, String>().put(TAG_CATEGORIES, "All"));

            //refreshing the contents of list to show newly added items
            adapter.notifyDataSetChanged();

            ListView lv = getListView();

            // Launching new screen on Selecting Single ListItem
            lv.setOnItemClickListener(new OnItemClickListener() {

                @SuppressWarnings("unchecked")
                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {

                    HashMap<String, String> map = new HashMap<String, String>();
                    map = (HashMap<String, String>) getListAdapter().getItem(position);

                    String categories = ((TextView) view.findViewById(R.id.categories)).getText().toString();

                    // Starting new intent
                    Intent in = new Intent(getApplicationContext(), ListVenueActivity.class);
                    in.putExtra(TAG_CATEGORIES, categories);
                    startActivity(in);
                }
            });
     }
}