Simple router.php for using the PHP 5.4 built-in webserver

router.php

<?php

    // Filename of requested file...
    $requested = __DIR__ . $_SERVER['REQUEST_URI'];

    // If file exists use file
    if (file_exists($requested) && !is_dir($requested)) {
        return false;
    }

    // Fallback
    include 'app.php';