If you need an app with UI, configuration options, or any hand-holding, this is not the app for you. If you are a privacy-conscious Android power-user and you want a rock-simple software kill switch of the microphone for the ENTIRE Android OS, you're in the right place.

"Mute Microphone" does what it says FOR ALL OF ANDROID and mutes the mic for all apps at once. If "Mute Microphone" is running, ANY APP that uses the microphone will not receive audio, INCLUDING THE PHONE APP. It is software kill switch with no "UI" other than a notification to shut it off (and re-enable the mic).

This "app" is meant for privacy conscious people that don't want the phone app, Google assistant, song-identifier, or any other app to potentially listen in. All apps that normally use the microphone will receive no audio while "Mute Microphone" is running. If you want to re-enable the microphone to talk on the phone with someone, click on the "Mute Microphone" notification and the app will enable the microphone for all apps and exit.

"Mute Microphone" is meant for privacy-conscious people and Android power-users that just want a software kill switch for the mic and don't need any sort of "user interface" or screens to control it. There is no "user interface" to get in your way other than launch-icon to start muting the microphone, and clicking the notification to stop and enable the microphone again.