This is a useful tech trick for those who would like to use their iPhone lying down in bed.
The iPhone has a ‘gyroscope’ within it that senses the orientation of the device at any time. It can be frustrating when using the iPhone and the gyroscope senses that the phone has changed orientation and flips the screen from portrait (vertical) to landscape (horizontal), or vice versa, when you would rather it stay put.
But there’s no need to drive yourself mad trying to hold the phone on strange angles so you can see it properly, you can simply lock the screen to stay in portrait.
To do this, first double-click the home button to bring up the open applications menu at the bottom of the screen. Then swipe the row of icons from left to right. You will see a grey icon on the left with a circular arrow. Tap this item to lock the orientation. A small padlock will appear in the middle of the arrow. To unlock the orientation just follow the same steps.