Mobile App PHP redirect

index.php

<?php
$ua = strtolower($_SERVER['HTTP_USER_AGENT']);
if(stripos($ua,'android') !== false) { // && stripos($ua,'mobile') !== false) {
  header('Location: https://MyAndroidAppURL');
  exit();
} else if(strstr($_SERVER['HTTP_USER_AGENT'],'iPhone') || strstr($_SERVER['HTTP_USER_AGENT'],'iPod') || strstr($_SERVER['HTTP_USER_AGENT'],'iPad'))
{
  header('Location: http://MyiTunesAppURL');
  exit();
} else {
  header('Location: http://MyWebsite');
  
  exit();
}

?>