One phone. Three jobs.
System requirements
CastSound system requirements: Android 8 or later or iOS 18.2 or later on your phone, a macOS or Linux computer, and the same Wi-Fi network or USB tethering.
Phone or tablet
Android 8 or later, or an iPhone/iPad running iOS 18.2 or later. Microphone, camera, and local-network permissions are required for their related features.
Computer
A supported macOS or Linux computer with working audio. macOS setup includes the CastSound audio components.
Connection
Both devices should be on the same local network. Guest networks may prevent devices from seeing one another. USB tethering is available as an alternative.