It could be that your wifi signal isn't strong enough. You could try downloading it to iTunes on your computer and syncing it to your iPhone.
3 replies
My internet is at a speed of 35mps, it's probably not the issue, and in addition to this, the iMovie app and a few others; it lets me download it again, since I don't have a working computer I can't sync it to my phone, but thanks for the effort i apprectiate it.
How much space is still available on your device?
I've downloaded numbers on the App Store and now I can't get it back