Okay so I have one main view controller and then I added a navigation view controller from the 'Editor -> Embed In -> Navigation Controller' toolbar and then I segued from the first view controller button to the empty navigation controller scene because if I segued directly to the signup or signin VC the main view controller would end up having a bar on the top like the navigation view controller. But now i added an bar button item "Back" and segued to the main VC and the bar comes back with a builtin back button. So how can i add a default back button or any back button without having the main VC becoming a navigation view controller. Here is a link to an image: https://www.dropbox.com/s/1623a45v846ijn8/Screen%20Shot%202015-09-27%20at%2012.23.26%20PM.png?dl=0
The problem is that you have two navigation controllers when you should only have one.
You should make your initial view controller a UINavigationController, and set your previous initial view controller as the root. If you don't want to see the bar, just set the bar to be hidden on your viewWillAppear, and unhide it on the Sign In / Sign Up pages.
