We are using custom fonts in our project. It works well in Xcode 5. In Xcode 6, it works in plain text, attributed string in code. But those attributed strings set in storyboard
@Hamidptb solution works, make sure to get the correct name of the font (once you've added it to Font Book)
Open the Font Book application, navigate to your font then press Command+I. The PostScript name is the font name you want to use here:
UILabel.appearance().font = UIFont(name: "PostScriptName", size: 17)