A free program for Android, by JT Lab.

This application can be used to listen to any sound from your surroundings. This is very useful in situations where you cannot use your phone’s microphone, such as when you’re in a meeting or an event. 

The sound is transmitted through the air to your phone, where it is converted into electrical signals and is then processed by the phone’s audio processor.

The resulting audio is then transmitted to the user, who can then use the phone’s built-in speaker or earpiece to listen to the audio.

This app is very simple to use and does not require any special setup. You will only need to open the app and start listening.