Library

inSSIDER
Purpose - WiFi network scanner on Windows/MAC desktops and Android Phones
Website - http://www.inssider.com
Cost - Paid Software

Netstumbler
Purpose - Tool for detection of WLAN on Windows based Systems
Website - http://www.netstumbler.com/downloads/
Cost - Freeware

Kismet
Purpose - Network detector, packet sniffer and IDS for WLAN on Linux, MAC OS and Windows systems
Website - http://www.kismetwireless.net/
Cost - Freeware

KisMAC
Website - http://kismac-ng.org/
Purpose - WLAN Network detector on MAC OS
Cost - Freeware

iStumbler
Website - http://istumbler.net/
Purpose - Wireless networks and devices scanner with Airport or Bluetooth-enabled Macintosh computers.
Cost - Freeware