iStumbler
iStumbler is the leading wireless discovery tool for macOS, with tools for investigating: Wi-Fi networks, Bluetooth devices, Bonjour services, Location information, and now 2.4 & 5 GHz Spectrum analysis with your Mac.
Release 103 adds a Live Map, Bluetooth LE Support, Real-Wave Spectrum View for WiPry devices, TouchBar support and many, many assorted bug fixes and enhancements.