software ... without the need to manually define ports and filters in the router.
You won't (I hope!), find it. Such software would be a high security risk. There are good security reasons why manual intervention is necessary to allow incoming Internet traffic onto a local network. Basically when sitting behind a router you have two options.
Firstly you could set up the router to place a single computer in a DMZ where all unknown incoming traffic to the routers IP address is forwarded. Such a computer is effectively open to the world and is a high security risk as it is also connected to your LAN so an attacker could potentially jump from that open computer to others on your LAN.
Or preferably, as I presume that you have already found, you set up the router to forward incoming traffic on a defined port to a single internal IP address on your LAN.
Either way explicit permission is required to allow that external traffic onto your LAN. Also while most routers have an option for remote configuration from the WAN this should
always be disabled unless absolutely necessary (and it almost never is) even though access to the router is password protected.