I have been using SoftPerfect's WiFi Guard for about 3 weeks and I LOVE it! It's a great little utility and just what I needed.
I have found a small bug. In the "Last Seen" column, some lines display 1357 months ago (which would be January 1900), so it seems that the software may be getting some date formats confused and defaulting to the earliest known date it can actually input. Hope to have this bug fixed! It is not a major issue for me, but could be a major issue for someone attempting to determine when a (possibly unauthorized) device last connected to their network.
A response is not required for this post in the effort to fix it, only a version update But feel free to post here should you also experience the same problem. That way we know that it's not just a problem with me!
You can download a fresh copy here and install over your existing one. Then click the Forget button against those devices with incorrect dates. They'll have a correct date whenever they are discovered again.