Volume+ has worked flawless on my Gnex since I purchased the app. Just have to start from a very low volume setting while you are streaming music to be able to get it the right volume. It was totally worth the 99cents.
I tried the free version for the Galaxy Nexus and it did not work, so I started reading on different forums and found that the paid version is the only one that works for the Nexus. for I have it set to 12 and it is just right for how loud it gets. If I set it to 13 or higher the speaker just rattles and the sound is really distorted.