WiFi Analyzer can help you to identify Wi-Fi problems, find the best channel or the best place for your router/access-point.

Vistumbler is open source WiFi scanner for windows.

Baidu WiFi Hotspot is a virtual hotspot creator app.

NetStumbler (Network Stumbler) is a tool for Windows that facilitates detection of Wireless LANs using the 802.11b, 802.11a and 802.11g WLAN standards.

WeFi is an app which connected to free wifi and cellular networks and provided analytic services.