Use The Camera Grid Setting

When the Grid mode option is turned on, you will see two horizontal and two vertical lines that intersect to create a total of nine equally divided boxes.

1. Open the settings on your home screen and go to Camera.
2. Go to Grid and turn on the switch. 

This will work for any iOS 7 and up . If you are still rocking the old school iPhones, you can access grid mode like this:

1. Open the camera app.
2. Go to options.
3. Find Grid and turn it on!