AudioRelay is described as 'Listen to your PC audio, use your phone as a mic or stream audio from your phone' and is a Audio Router in the audio & music category. There are more than 10 alternatives to AudioRelay for a variety of platforms, including Windows, Linux, Android, Mac and iPhone apps. The best AudioRelay alternative is Audio Share, which is both free and Open Source. Other great apps like AudioRelay are SonoBus, Airfoil, PairPods and SoundWire.
Audio Share can share Windows/Linux computer's audio to Android phone over network, so your phone becomes the speaker of computer. (You needn't buy a new speaker😄.).
Audio Share is the most popular Windows, Android & Linux alternative to AudioRelay.
Audio Share is the most popular Open Source & free alternative to AudioRelay.
SonoBus is an easy to use application for streaming high-quality, low-latency peer-to-peer audio between devices over the internet or a local network.
SonoBus is the most popular Mac, iPhone & iPad alternative to AudioRelay.
Send any audio to the AirPort Express. Send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! Airfoil for Mac gives you your audio - everywhere.
A macOS menubar app that lets you share audio between two Bluetooth devices simultaneously. PairPods makes it easy to create shared listening experiences.
SoundWire lets you send any music or audio ("what you hear now") from your Windows or Linux PC to your Android mobile devices.
Utility for turning your Android smartphone or tablet into a wireless speaker.
Name changed and it's filled with ads now, forcing you to pay to remove them. Also something about a bundled forced game in one of the reviews.
WiFi Audio Wireless Speaker is the most popular Android Tablet alternative to AudioRelay.
Snapcast enhances audio players, creating a multiroom solution with synchronized playback via client-server architecture. It allows simultaneous audio feeds and client grouping, integrating well with MPD and Mopidy for perfect audio distribution.
Stream What You Hear (SWYH) is a Windows application to broadcast the sound of your computer (ie: “what you hear”) on an UPnP/DLNA device such as TVs, amps, network receivers, game consoles, etc...
SoundShare brings seamless audio sharing to macOS, allowing you to connect multiple Bluetooth audio devices and share music, podcasts, or videos with friends.
SoundShare - Audio Sharing is the most popular commercial alternative to AudioRelay.
Audio Source forwards Android microphone audio input to the PulseAudio daemon through ADB, so you can use your Android device as a USB microphone.
Redirects and centralizes audio between PCs, enabling sound transfer across network for applications like chat, music, and alerts with easy toggling and up to four shared installations.
WO Mic can turn your phone to be a microphone for your computer. Millions of people have installed it and are using it daily for talking, recording, voice remote control and many other activities.
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Not even close as alternative, Sonobus it's oriented into a Discord-like functionality, AudioRelay shares audio from your PC to your phone, completely different purposes.