I have been using WifiGuard quite a lot as a free application for my home PC, in version 1.X, and upgraded it to 2.0. But version 2.0 does not display properly some of the scanned IP addresses.
Some do as 192.168.5.3 Machine A, but some others display the same line 192.168.5.* with Mac Address as *-*-*-*-*-* with no name and several times in fact as many times as some machines are on the network. I came back to version 1.0.4 which i kept. Can anybody clarify?
As of version 2.0, WiFi Guard is a paid app. In the free demo version it shows a limited number of devices and the rest is displayed with asterisks.
You can see that change in the changelog and it's stated on the application home page:
Unlimited duration trial with maximum of 5 devices displayed
If you prefer to remain a freeware user, you can disable update notifications and continue using the free version you already have for as long as you like. Make sure you keep a copy of the files, as freeware downloads are no longer available.