Over on YouTube user RickMakes has uploaded a video showing how to install and use CubicSDR on a Mac computer. CubicSDR is a general purpose program compatible with multiple SDRs including the RTL-SDR and is one of the few SDR programs available for use on MacOS.
The installation is as simple as downloading the .dmg file from the CubicSDR GitHub page and running the automatic installer. Afterwards you can move the program to your Applications folder. Once opened CubicSDR should then automatically detect any RTL-SDR that is plugged in.
In the rest of the video RickMakes demonstrates CubicSDR and the RTL-SDR in action, receiving various broadcast FM and ISM band signals.
CubicSDR Basic Setup on Mac with RTL-SDR Blog V3