Quality!

+Extremely good bass quality, after going through 6 other "Bass boost" apps, this one can increase bass without compromising the quality of the sound, recommended bass boost 3.0 or below (Youll see)?

+Has a very sleek UI, doesnt look cheap, and can easily compare to flagship default apps.

+Audio Visualizers are very responsive and most importantly of all they work with bluetooth

+On top of the bass boost feature, has a built in equalizer which also works perfectly.

This is one of the only music apps i use aside from the default IOS app

HeeroX about Equalizer+ Pro HD music player, v2.4.4