Apple iphone 4s apps not updating
Because of that, whenever you try to open an app, i OS fails to validate your i Tunes password to ensure that you are actually entitled to run the app (due to the personal and sensitive information that the app might contain), causing it to crash upon opening.
So if this happens with i OS 9, you shouldn't feel like you're alone.
In this case the solution is more straightforward: Just delete the app and re-download it.
Apple is constantly updating and changing the binaries it distributes.
What is even more, app binaries seem to be sometimes different per region, which explains some users being able to open the app normally while other face sudden crashes. If the app keeps crashing, then wait a few hours or days and try again.
The new copy of your app should then open and work without a hitch.