I have used (Free) inSSIDer for several years now, both Version 2 and Version 3 (the latter to a lesser degree).
Both versions only show working WiFi channels - they do NOT do the Spectrum Analysis
required for NON-WiFi Transmissions.
My understanding from the metageek site, is that WiSpy H/W and S/W adds the Spectrum Analysis ability, showing
all signals and noise occurring in the WiFi band.
From the metageek site-
Wi-Fi uses the same frequencies as wireless consumer electronics.
In its most basic form, Wi-Fi is radio waves that travel in the 2.4 GHz or 5 GHz bands. When two devices transmit simultaneously, their waves cancel each other out. These collisions are undetected by Wi-Fi cards, but the resulting network slowness or complete loss of connectivity is painfully obvious to humans.