The free edition has a simple but attractive GUI. The 3.1 version looked at here offers some great wireless details and graphs. Tarlogic Security offers Acrylic Wi-Fi Home, a Wi-Fi stumbler that is a scaled down version of their commercial offering. Most of these tools are the free versions of for-pay tools made by the same vendors, and lack some of the features included in the commercial versions.
One of them includes Wi-Fi password-cracking tools that are useful for educational or penetration testing purposes. Some can even reveal “hidden” or non-broadcasted SSIDs, display the noise levels, or display statistics on successful and failed packets of your wireless connection. Here is a look at eight free tools – some for Windows and some for Mac OS X – that provide basic details about nearby Wi-Fi signals: SSIDs, signal strength, channels, MAC addresses and security status. There is enterprise-level software for surveying Wi-Fi networks, but even in large wireless networks, simple freeware tools are handy for a quick peek at the airwaves during design, deployment or troubleshooting.