Hey @daver! Fortunately, this is a very easy fix. You don’t need to port forward anything. Just use the IP 127.0.0.1 and the port 8080 for the OpenSprinkler IP:Port in the web app.
The 127.0.0.1 is your loopback interface which routes traffic back to the same machine. Since you are using the same Raspberry Pi for the interval program and the web app we can use the loopback.
The port 8080 is what the interval program uses by default. My web app is asking about this IP:port. This is because my web app communicates with the interval app.
Hope this makes sense and helps.
Update: Well, if you want to access the mobile web app outside of the home you port forward 80.