If you would like for your iPhone to be louder and you aren’t sure how to adjust the standard volume, just tap Settings, then Sounds and tap and drag the slider to the right. If you all ready have the regular volume turned all the way up and still and want more, then there are a few apps you can get that will boost your sound. Volume Boost + is available at the iTunes store for 99 cents. If your iPhone is jailbroken, then Volume Amplifier, which is available through Cydia is a good choice. That app costs $1.99.