Firmware version is 4.31_3B14 and you must upgrade.
Like Felix said, it is basically a web-based interface into the Apex. It'll store history, display graphs, allow you to modify settings, etc. All this can be done presumably without the need for the port-forwarding. Setting up the home routers seems to be a sticky point for many people.
Having said all of that, I don't seem to be able to control my unit through the Fusion pages. Monitor, certainly; but not control. I seem to have more playing to do.