Some apps won't run after upgrade to iOS 7.1, how to fix?
Try shutting down all apps by double clicking the home button, then swiping all of the apps up to the top of the screen to quit them then reboot your phone by holding down the Home &amp; Power button at the same time until it prompts you to shut down.

Go ahead and restart it again. If it still won't fully launch, you may have gotten a bum download. To delete the app, tap and hold on the icon until the 'x' appears and tap that 'x'. Go back to the app store and then reinstall the app and give it another try.