The back button is almost universally located in the upper left corner and is accompanied by the standard swipe right gesture to pop the top of the stack. You'r

The back button is almost universally located in the upper left corner and is accompanied by the standard swipe right gesture to pop the top of the stack. You're not going to find many apps that implement a custom navigation controller in iOS, and if an app does then it probably doesn't change this behavior. The same goes for the swipe to delete accessory item, as that is another standard iOS UIKit thing. I can't speak for minor buttons like edit and compose etc, but those differences are honestly not very significant to the end user since it's a non-hidden textual nav item.