With Headset Remote, user Android device becomes a microphone, transmit voice to remote bluetooth headset in wireless. That means, this app will turn on built-in speaker, voice transmit to connected bluetooth earbuds. If there are 2 Android phones and 2 set of headsets, users can talk to each other without phone call. How to use: Turn on Android bluetooth, connect to your bluetooth headphone. Start this app, try music 1 or music 2 first, to make sure the sound audio goes to the bluetooth heads