For the debate that CDM, Jayson A and lagwagon are having:
During the initial iOS 9 betas I found several apps that weren't functioning properly while testing. It ended up being a mix of new/modified Apple coding, and the 3rd party app dev coding. Found this out by submitting bug reports to apple as well as the app devs, which really is the entire point of running a beta...to test and report. TL;DR - it is entirely possible for an app to function one way, and an entirely different way between iOS versions. This is not the fault of Apple. Devs are just as responsible for updating their apps, as Apple is responsible for fixing bugs. Apple updates the OS, devs update their apps. This has been going on for many years now.
Side note - the bickering on these forums is truly out of control. I've stopped coming here lately and stared posting over on Reddit instead, because every other thread is cluttered up with nonsensical arguments and off topic posts. Come on, guys.
That's funny, but Apple's own built in apps need to be updated then in order to work properly with iOS 9.
Listen, on my iPhone, I don't use any third party apps.