My iPhone 4 won't let me download any apps?

I've tried turning it off but it's still the same. When I download an app it says waiting but then it says " Unable to download application this app could not download at this time" this has been for the past two days. What can I do? Please help!

It s probably just the app, but if the app is that inportiant to you, you can reset your iphone, but for sure back it up on itunes first, also you can also try calling apple.

That happens to me all the time, all you have to do it connect your iPhone to iTunes and download the app from the computer.

Update or Reformat.