I'm not quite sure what you wanted, so I'll answer most of what I think you could want for your sake and anyone looking at this in the future.
First: You want a back button similar to those on default apple apps. To do so, you need to a) get a reference to the destination scene and it's view controller. I will assume you have done so and set it equal to controller
for future reference. b) You need to set the left bar button item. Set it with:
controller.navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Insert Title Here!!", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)
Place all of this in prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
(you will also find the destination scene with this, likely with segue.destinationViewController
Second: You want to use an image named "Back" for all items. If so, repeat step a) above, and insert this handy bit of code:
UIBarButtonItem(image: "Back", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)
I also know you want to not have to copy it, but it's not as if this is that computer intensive anyways and it's probably simplest.
Third: You're smart and don't hate advances in programming so you want to use a storyboard. If so, simply drag in a Navigation Bar from the object menu, add a navigation item, and copy it to all of your scenes. If your scenes are linked to custom classes, then super happy fun time good news, you can simply link the navigation item to your custom class through an IBAction
and use that function to do all the fancy coding your heart could ever desire.
Fourth: You really, really don't want to copy anything even if it's not that hard. If so, you can subclass a UIViewController with your own custom class, add the code I mentioned above, and then subclass all your future UIView classes as this. To be honest, I'm not entirely sure this would work and it seems unnecessarily laborious, but it's up to you.
I'm a bit tired right now so sorry for all the things I'm finding funny, but I hope I helped, and please tell me if I missed your point entirely and I can try and think of a solution.