Anyway, you can also choose to add apps or instead remove them to appear on Notifications Center like disabling Stock Widget. So to add or remove your preferred apps in the Notifications Center follow these steps...
1. On your iPhone home screen, tap the Settings app!
2. Tap on “Notifications” in the settings area.
3.See all the apps listed in the "Not in Notification Center" area, and tap one of the apps you'd like to be added to Notification Center.
4. Tap the toggle switch next to “Notification Center” so it is set to "ON". Or if you want to remove the app then set to "OFF".