I know a guy can set a static IP etc etc but the problem is that IP may not align with the variations of routers out there...
I would think somehow this would be possible so that no matter what DHCP assigns for an IP you could just go to www.whatismyip.com and use that IP I think this would be a very effective thing to help the not so network savvy.
After all it is used by some of the top programs out there to forward ports automatically I am sure this same method could somehow be used for basic as well providing the code is not insane.
Just a thought UPNP port fwd would be interesting while not a needed thing what it would provide would be worthwhile.
I know there are security issues with UPNP but most have been cleared up or at least the remote access forwarding by rules that only allow the port forwards to the specific IP if I recall correct anyhow just a suggestion for an addition.
Where I buy my ESP8266 boards from... (Banggood)