Question: a must have apps for iphone?
Answer: Google Maps (Free) Sure, you have the official iPhone navigator app “Maps.” But if you want an app that fully delivers, add Google Maps to your list. ... 
BillGuard (Free) ... 
Buffer (Free) ... 
Dashlane (Free) ... 
Zillow (Free) ... 
Fooducate (Free) ... 
Sleep Cycle ($1.99) ... 
Dropbox (Free)