better_guestbook/api/settings/appname.php

<?php
// Load Main Library
require "../api.php";

$api = new gbAPI(false);

// Get App Name
$command = "SELECT name, value FROM settings WHERE name = :name";
$result = $api->dbCommand($command, true, true, [":name" => "application_name"]);

$api->answer(200, [
    "application_name" => $result["value"]
]);