There is a reason why in countries like Saudi Arabia, Egypt and Lebanon, there is a select body of scholars mandated to endorse published hard copies of the mus-haf. This is because there have been numerous attempts by non-Muslims and pseudo Islamic groups to insert or expunge the parts of the Quran that do not tally with their sectarial ideologies. Of course, the language of the Quran is distinct, and its form outstanding, but an unwary Muslim, especially one who does not understand Arabic, may fall into the trap of using a fake mus-haf as a reference or a means for recital. The following listed Quran apps have been accused of not being accurate...

http://i.imgur.com/edqgL.jpgo

Please recite from an endorsed hard copy mus-haf or better still, memorise the Quran and recite from memory.