Hello Nier0525,
Thanks for using Apple Support Communities.
I see that you're getting an apps could not be installed at this time error after a few minutes of downloading. I have several things for you to check.
First, it's important to make sure that you have a recent backup of your iPhone's important data. Use this article to confirm a recent backup How to back up your devices using iCloud or iTunes
Next, let's make sure that you have the latest iOS software updates. In your post, it says you're running iOS 7.1.1. It's always a good idea to have the latest software release installed. Use this article to help get the updated software Update the iOS software on your iPhone, iPad, or iPod touch
And finally, you'll want to make sure you have a good Wi-Fi or Cellular connection when downloading and installing these apps.
Additional information can be found in this article Use the App Store on your iOS devices, Apple TV, or computer.
Cheers!