Volume booster?

[Branson_f]

Is there a good app that will boost the music volume on the iPhone? I wish it was louder than it is.

 

[Primetime]

Nope.. In your case you should buy an external device plugged into the headphone jack. ie speakers of some sort. That is of course I'm assuming you want it louder for music. I can't imagine you need it louder for regular usage of the phone like hearing it ring etc.

 

[Phazer]

Try This method

Increase Speaker and Headphone Volume Of iPhone

It works for my iPhone 4 (Non-US).. And believe me,, It will blow off your ear