App stuck in "waiting" mode

I previously had the Mediafire app to access some files I have stored there. I uninstalled the app a few weeks ago, then I had to reinstall it.

When I went to reinstall it, the app got stuck in "Waiting" mode. I cannot delete the box on my home page that says "waiting". Going to the App store and searching for "Mediafire" reveals the box with a circle around it (for stop). When I hit the box, it fades, but nothing happens. If I search again, I just get the box with the circle around it again. How can I fix this?

I have tried:

1) Restarting iPhone

2) Signing out of app store, re-signing back in

3) Force restarting iPhone

4) Plugging in to iTunes on my PC to manage apps (apps do not show up properly through iTunes).