Latest iOS versions like iOS 8 and iOS 7, rotation lock feature is moved to Control Center.
If you enable rotation lock option, it will prevent your iPhone or iPad screen from automatically changing its screen orientation when your iPhone or iPod is turned.
If you want to access Control Center settings and lock rotation option in iOS 8/7 follow my steps:
Step 1: Swipe up from the iPhone home screen bottom to bring the Control center.
Step 2: Control center top row shows 5 circular toggles. Press the (arrow around a padlock) icon to enable or disable you device rotation lock.
Step 3: Swipe down to close the control center.
Note : Some apps don’t stop rotation when your turn your phone.
On older iOS versions
- Double click the Home key to access iPad background control screen.
- Swipe-right until you see the orientation controls.
- Tap the portrait orientation lock button.