A free program for Android, by Live Video Tool.

Live Microphone – Wireless Mic is a simple app that sends audio from the mic to the speaker. You can use it for voice chatting, recording, and recognition. It also provides you with a way to control the voice quality and echo sound.

It supports the localisation/tasker as a plugin.

You can pop, rap, or perform with this app.

It can be used in many different ways, such as giving presentations, announcements in railways, schools, and public places where you have to use a microphone to speak to a large audience.

You can use it in recording, live music, or singing.