Airfoil - This software is from the Rogue Amoeba company, built to run on Mac and Windows platforms. It’s an audio-based software that allows the computers sound to play over a network device. Read more about Airfoil.

Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning

SoundWire - SoundWire does audio mirroring (audio cast). You can use any music player on your PC or laptop like Spotify, YouTube, or iTunes and stream low-latency live sound over WiFi directly to your Android device.

YakYak - Desktop client for Google Hangouts

AudioRelay - Listen to your PC audio, use your phone as a mic or stream audio from your phone

PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).