Every device has a built-in Android eQualizer. <font color="#d71b5f">Volume Booster Pro</font> simply adjusts the frequencies to achieve louder effect. We use the loudness module which runs on devices with Android 4.4, you simply need to tap the <font color="#d71b5f">Boost</font> button.
Use the demo song to spot the difference and adjust the desired level of the effect.
Older version should use the slider only.
For maximum results use external <font color="#d71b5f">speakers</font> or <font color="#d71b5f">headsets</font>.
Ringtone: https://goo.gl/U3re2h

Listening music too loud is bad for your ears.