Volume boost app?

Is it true that there is no working volume boost app for Android 4.2?

I installed an aux cable in my car but the volume from the FP is too low which makes the sound quality very poor.

No, that’s not true. If you search Google’s play store (or the web) you’ll find a plethora of volume boost apps for Android 2.3 and above.
Whether they are good or not is another thing, and not using any myself I can’t say anithing about that.

Yes there are quite a few apps claiming to boost volume but as far as I can see, none of them are actually working with 4.2 and later.

/Lars

OK…

googling suggests that, since the FP is rooted, there are possibilities to hack the audio system files. But it also seems as if the guides for hacking are device-specific (e.g. one procedure for Samsung, another for HTC and so on). No idea how to fix this on a FP.