Additional Notes on Accessing the Application from Outside your Local Network
Please take the utmost care in considering options for exposing this application outside of your home network. Given that this application has very limited security built-in, anyone that is able to gain access to it directly or indirectly, may be able to control your hardware which could result in damage to your property or even potentially physical harm to someone nearby.
If you want to have access to this application outside of your home network, and I haven't already convinced you not to do this, then I would recommend setting up a VPN for your local network. This would allow you to tunnel to your home network and access all of your local equipment with some level of security. A good, low cost, and dead simple VPN project I would recommend is PiVPN.