Hello,
I am a web developer and can finish your app in seven days with delivery and hosting, ready for production. I work every day on web applications using core PHP and MySQL, JavaSciprt, HTML, CSS. I can also use firebase if you want your simple app to be hosted there and use the real-time services provided by that service. If you already have something in mind just let me know and I will try to bring it to life.
Best regards,
Mohessaid