Throttling/Restricting localtunnel-server traffic

Question

We've developed a server software and for ease of use for end-users, we are using the localtunnel-server app on one of our linux servers to get around the need for port forwarding and messing around with firewalls.

The problem is that it seems to tunnel "all" traffic on the port 80. However, we are afraid of this being abused. We would like to restrict traffic somehow and I wanted to know if that was even possible.

For example, let's say our app uses the "/myapp" virtual directory on the localhost website. So if a request is supposed to go to http://localhost/myapp/index.html then the traffic gets tunneled to http://mytunnel.myserver.com/myapp/index.html

The problem is, if there are other sites running on localhost, http://localhost/someotherapp also gets through. We'd like to block urls that don't match a format or contain keywords such as "/myapp"

Is that even possible? And if so, any guidance on how to achieve this, would be greatly appreciated.