Loudest sound - earbud booster

Loudest sound booster - earbud booster is Simple, small, free app to boost your speaker or headphone sound volume. Useful for movies, audio books and music. Use at your own risk. Playing audio at high volumes, especially for a prolonged amount of time, can destroy speakers and/or damage hearing. Some users HAVE reported destroyed speakers and earphones. If you hear distorted audio, lower the volume (but it may be too late).

This is not for adjusting the speakerphone volume in phone calls (that has its own boost, I think), but for adjusting the volume of music, movies and apps.