There is an article from MusicRadar -
11 of the best iPhone/iPad iOS effects processors
Our pick of the top effects on the App Store
and Audio Mastering for iPad is here!
Next interesting review -
"Audio Mastering App for iPad – You should get this if you record audio…"
from iPad and Technology in Music Education
and finally the latest issue of Film & Game Composer online magazine with article about Master FX app -
Film & Game Composer issue 1 Feb 2014 (PDF file)