If the option is missing XCode shows the following warning.
Pods/ViewDeck/ViewDeck/IIViewDeckController.m:950:39: '__bridge' casts have no effect when not using ARC
Well, it doesn't require ARC. I've been thinking of making it ARC only though. I don't think there's a lot of people there using non-ARC mode, and there's always -fobjc-arc.
On the other hand, indicating 'requires arc' doesn't hurt either.
, this is the last warning in our project :)