My iPhone 5s camera has broken?

I've had my iPhone 5s for about a month and a bit and have no problems what so ever. But all of a sudden my camera stoped working. When using anything that uses my front camera it freezes and my camera refuses to work this is all after I updated iOS 8 i have done some things that fixed it but the problem returned again I just want to know if there's anything I can do before taking it to an Apple Store.

Yes. Connect the phone to your host computer and use iTunes to create a full back-up, including the apps. Play safe and repeat the back-up to iCloud as well.

Next, eject the phone from iTunes and go to Settings>General>Reset>Erase all content and settings. I can't recall whether that involves rebooting the phone but if it doesn't, do so.

Set the phone up again as if it's brand new and then check whether the camera works. If it does then you know that an app you added is causing trouble. Connect it back to iTunes on your host computer and restore your back-up; if the problem returns then you've confirmed the cause. Delete individual apps you've added one at a time to see which one is the culprit.

If that doesn't sort it out, return the phone to Apple under your AppleCare warranty; make sure you carry out another full back-up before doing so as Apple are more likely to replace the phone rather than repair it immediately, and even if they do repair it immediately they'll routinely wipe the phone back to factory settings. Your fresh back-up ensures that whichever option occurs you'll quickly have the phone back the way you like it.