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.

inSSIDer - inSSIDer Essential makes it easy to maintain small business WiFi.

Zabbix - Track, record, alert and visualize performance and availability of IT resources

NetStumbler - Official source of information about Netstumbler.

Abusix - Abusix is a network security company that offers email threat protection and network abuse handling solutions to ISPs, Telcos, and Cloud/Hosting Providers to stop the rapidly growing problem of email-borne threats and other kinds of network abuse.

NetSpot - NetSpot is a free app for wireless site surveys, Wi-Fi analysis, and troubleshooting