[Joomla!] - Create standalone application

app.php

<?php
/** 
 * Custom standalone application
 *
 * @package Joomla.Cli
 * @application Stand-alone
 */ 
define('_JEXEC', 1);
ini_set('magic_quotes_runtime', 0);
ini_set('max_execution_time', 0);

if(file_exists(dirname(dirname(__FILE__)).'/defines.php')){
	require_once dirname(dirname(__FILE__)).'/defines.php';
}

if(!defined('_JDEFINES')){
	define('JPATH_BASE', dirname(dirname(__FILE__)));
	require_once JPATH_BASE.'/includes/defines.php';
}

require_once JPATH_LIBRARIES.'/import.php';
require_once JPATH_LIBRARIES.'/cms.php';
JError::$legacy = true;
require_once JPATH_CONFIGURATION.'/configuration.php';

/**
 * Custom application class
 */
class CustomApplication extends JApplicationWeb {
  protected function doExecute(){
    $code   = 'Code';
    $site   = JURI::current();
    $return = $site.' - '.$code.' Example';
    
    // Displays view
    $this->setBody($return);
  }
}

// Instantiate the application.
$application = CustomApplication::getInstance('CustomApplication');
 
// Run the application
$application->execute();