Bass Booster, our second app, is on Google Play. It's still a beta-version and it's likely to not work on your phone if it's not rooted, but give it a try !
https://play.google.com/store/apps/details?id=com.desaxedstudios.bassbooster
It allow you to boost the bass of your speakers/headphones and equalize the sound !
Don't forget to read the description on the Play Store !