Turn your phone into a Bluetooth Microphone.
This is a low latency application that allows you to amplify and send raw microphone data to a Bluetooth capable speaker. You need to be connected to a Bluetooth speaker for this application to work properly.
Once connected to a Bluetooth speaker open this application and flip the on switch. Then adjust the volume by swiping left or right on the volume knob. Then speak into your phone's mic to hear your voice through the Bluetooth speaker.
This application is developed in C using OpenSL ES. This is a low latency implementation.