Static Z Software has released Sound Siphon 3, a feature update to their audio capture application for macOS.
Use it to create virtual input audio devices that send audio from one app to another or, record right in the Sound Siphon app. Version 3 adds a new interface, fully configurable channel mapping, and a live mixer.
Sound Siphon requires macOS 10.11 or higher. It costs $49; a demo is available for download (https://staticz.com/soundsiphon/).