I recently bought a Phantom 4 and when I put my iPhone 6 Plus on the Transmitter in the carrier it sits in the vertical position and is unable to go into the horizontal position as it does not fit.
Now my problem is that the display is permanently in the horizontal  when I look at the flight menu. Now you see my problem I'm unable to see the flight programme unless I turn the transmitter on its side, and that's not safe when flying a copter when you need to change something on the flight programme.
Any suggestions folks, I've checked with Apple and their suggestion doesn't work on the dji go App.
Cheers.
Bill

There are tabs on either side of the device holder about 1/2 way down from the top.   Use your fingernail to pry the tops of tabs forward and they will act as stops for your phone so you can mount it sideways.

See page 5 of the Phantom 4 Quick Start Guide.

Edit..  That should be Page 3  

jwt873@gmail.co Posted at 2016-4-11 16:55
There are tabs on either side of the device holder about 1/2 way down from the top.   Use your finge ...

Thank you very much that was something I never thought of. Thought I might have to go down the road of buying a new iPad that would fit. Again thank you very much.

Hope it could help you :