Microphone

Microphone is an advanced microphone app. Is can serve you for testing your device's microphone and speaker, you can use it as external mic or as a megaphone.

App offers different microphone input/output modes to use it on AUX or bluetooth external devices. Unfortunately, all input/output combinations are currently not possible on Android. You can also tune the sound by using the equalizer and boost the volume when using it as a megaphone.