iPhone app and iTunes?

[Andrej]

There are a few things you might check.
1) Depending what your iOS version is, Double Tap Home buttong to check the processes. Kill App Store and iTunes Processes, and if for some reason you have Facebook Process there, kill it as well.
2)If it doesnt work, Hold Power and Home button together and dont let go until you see Apple logo on your screen.
3)Go to Settings and Notifications to see if Facebook App is still there, but it shouldn't if you did 2).
4)Now, before you get your laptop back and running, you can also create your own facebook app. Simple by opening Safari, typing facebook url, then after the page has loaded, tap the bookmark icon and select Add to Home Screen.

Good Luck.
Sometimes iOS are weird, but it happens once in 1000 years.