AskQuit

using UnityEngine;
using System.Collections;
/// <summary>
/// An extra script for this repository: https://github.com/paganini24/UnityAndroidExtraPlugins
/// </summary>
public class AskQuit : MonoBehaviour {
    public float timeTreshold = 2f;
    float timeCounter = 0f;
    int count = 0;

    void Start ()
    {
        UnityAndroidExtras.instance.Init();
    }


    void Update () {
        if(Input.GetKeyDown(KeyCode.Escape))
        {
            count++;
            if (count == 1)
            {
                UnityAndroidExtras.instance.makeToast("Please press back button again to exit", 1);
            }
            else if (count == 2 && timeCounter < timeTreshold)
            {
                Application.Quit();
            }
        }
        // count time if clicked first time
        if(count == 1)
        {
            timeCounter += Time.deltaTime;
        }
        if(timeCounter > timeTreshold)
        {
            timeCounter = 0f;
            count = 0;
        }
    }
}