Why isn't my iPhone letting me download apps?

I've been trying to download some apps on my iPhone and it's not letting me for some reason. I tried restarting my phone and it still doesn't work. I'm not sure if it has anything to do with it but before this happened I updated my phone to IOS 8.4.

The only thing I can think of is that you don't have any storage but I suggest going to a local store that works on phones and electronics maybe an Apple Store if there's one near you or you can send it in to Apple

Try signing out & back in to your Apple ID account.

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