This is a wrapper script that simplifies deployment of RPiPlay, which does the heavy lifting. How well does it work?
Screen mirroring and audio works for iOS 9 or newer. Recent macOS versions also seem to be compatible. The GPU is used for decoding the h264 video stream. The Pi has no hardware acceleration for audio (AirPlay mirroring uses AAC), so the FDK-AAC decoder is used for that.
Both audio and video work fine on a Raspberry Pi 3B+ and a Raspberry Pi Zero, though playback is a bit smoother on the 3B+