How to add an iOS 8 widget and change order on iPhone.
How to Add iOS 8 Widgets
To add an iOS 8 widget to the notification center pull down to see the Notification Center -> scroll to the bottom and tap Edit. Widgets you installed will show at the very bottom of the screen.
Tap the small Plus icon to add to the Notification Center -> Use the three bars to the right to change position and the minus sign to remove them from your Notification Center. You can add them back in later and change the position as much as you want.
