Pretty basic, bare-bones wifi scanning tool - probably not worth the $5, as there are lots of free and open source alternatives.
Zaib Kaleem on inSSIDer for Mac OS X:
inSSIDer, the app we all have loved on Windows is now available on the Mac App Store.
See description below from the Mac App Store for details.The app looks very similar to the windows version but is currently a v1.0 product and doesn’t have all features of the windows version. I’m sure future versions will add all the great features available in the windows version. I have always liked the clean design of MetaGeek apps and looks like they were able continue with same design in Mac version of inSSIDer .
A big congrats and thanks to the MeteGeek folks for releasing a Mac version of inSSIDer!Scan the Wi-Fi networks around you and track their signal strength over time. inSSIDer scans all the Wi-Fi networks within the reach of your computer’s wireless card, tracks their signal strength over time, and determines their security settings. Track open or secure wireless networks. Determine the best channel for your own wireless network.