JSCloud

<html>
    <head>
        <title>JSCloud Demo</title>
        <script type="text/javascript" src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
        <script type="text/javascript" src="https://raw.githubusercontent.com/trvrsalom/JSCloud/master/web/jscloud.min.js"></script>
    </head>
    <body>
        <script type="text/javascript">
            var cloud = new JSCloud("https://you.com/jscloud.php");
            cloud.open("/data/data.json");
            cloud.write("users", "['johnsmith', 'mickey', 'oswin']");
            cloud.write("supersecret", "shhhh");
            var user = JSON.parse(cloud.read("users"))[1];
            cloud.delete("supersecret");
        </script>
    </body>
</html>
It's simple, fast, and easy. Oh. And it's free.