As I am not much into gaming and loves content apps more, my must have iPhone apps are..
The Pillars of The Earth
C&EN Mobile
MSK Injections
Mr.Boston Official Mobile bartender's Guide
The adventure of Sherlock Holmes
My must have 5 iPhone apps are
The pillars of the earth
Mr.Boston official bartender's guide
The adventures of Sherlock Holmes
C&EN Mobile
and Five little monkeys for my kid.