Video Sound Equalizer is a simple apps that let's you modify audio parameters in every video file. Then you can share the result files with your friends.
It usually supports modifying the following frequencies:
* 60Hz
* 230Hz
* 910Hz
* 3KHz
* 14KHz
(but it might change between different devices)
** YOU CAN ALSO BOOST THE VOLUME OF YOUR VIDEO FILE BY 400% WITH A SINGLE CLICK **