TamoGraph Site Survey - Wi-Fi site coverage survey and modelling application
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
iBwave Wi-Fi - iBwave Wi-Fi software suite brings smart networking solutions to enterprise, education, hospitality, transportation, retail, office, healthcare, public venues, and residential wireless networks.
netcat - Netcat is a featured networking utility which reads and writes data across network connections...
Waircut - Free network audit app
Ettercap - Ettercap is a suite for man in the middle attacks on LAN.