I tried a few of the IPhone WiFi scanners, nothing to write home to mom about. Until I tried WiFiFoFum scanner. It reminds me of Netstumber from back in the day, but with the GPS option. This scanner not only scans for WiFi networks, but it also records the location via GPS for later review. It records the data in a KML file that you can email yourself and drop into google maps or review right from your IPhone.
There are 4 radio buttons:
Networks - This button displays the basics ~ SSID, mac address, RSSI, data rates and if the network
is secure.
Radar - Pretty useless. It gives you a visual of how close you are. If you are in the crosshairs you are on the money.
Logging - The logging function is pretty cool. When you enable logging it will record your position when your IPhone heard the access point. Once you stop the logging it records your data in a file with the date and time. You click on that file and a google map pops up showing you the access points it found. You can also send yourself the file, its in a KML file.
Settings - The last button is the settings button. All the basic here, scan rate, RSSI filter, etc.