This post will show you how to turn off app auto update on iphone.
if you have a limited data plan then you might want to do this as the updates tend to eat all your data allowance.
to disable the app auto updates:
goto settings > itunes & app store
scroll down to ‘automatic downloads’
to disable the app auto updates all-together, toggle the ‘updates’ switch to off
to keep auto updates on, but restricted to wifi-only, keep the ‘updates’ switch on, but toggle the ‘use cellular data’ switch to off.