My Twitter icon is gone but still installed (iPhone)?

[its a bright sunshiney day]

I just got the new iPhone so I'm assuming it's running on the latest OS? Anyway, yesterday I was using the Twitter app. It started acting up all of a sudden. It would close immediately after I'd open it. Then I'd click the icon and it wouldn't open at all. Then the icon disappeared altogether. It's still installed though. When I go to the app store it only gives me the option to open the app, but when I press open it won't. -.- I've checked the other pages and the icon is definitely gone. What do I do? I've tried to restart the phone and it still won't come back. Any solutions?

[ѕσмєgυy]

Is it possible that you're running out of space?

Delete some apps (or other data) and try to access it again.