inSSIDer - inSSIDer Essential makes it easy to maintain small business WiFi.
OpenWiFiSpots - Hotspot location app
NetSpot - NetSpot is a free app for wireless site surveys, Wi-Fi analysis, and troubleshooting
Wi-Fi Space - Hotspot location app
Vistumbler - Vistumbler is a wireless network scanner for Windows Vista and Windows 7. Features:
yFi - macOS utility app to monitor your WiFi connection.