Speaker Booster Pro is an app that will improve the sound of your speakers and headphones by means of an algorithm that makes the audio louder and more clear. This app can increase the volume of your audio files by a factor of two or three. It is compatible with most Android devices. 

How to use Speaker Booster Pro

Open the app and connect your Android device to your speakers or headphones.

Select the volume to be increased.

If you want to increase the volume to the maximum, select "Full spectrum".

If you want to decrease the volume, select "Minimum".