Some files on my Swift project, like circle.yml and .gitignore, aren't shown in the Xcode 9 Navigator. How do I get them so show up?
The Xcode project navigator is not a file browser. Just because something is in your project folder, doesn't mean the project is aware of it. The project isn't magically watching the project folder to see what's put in there. It knows about the stuff that it put in there, of course. But you want something to be seen by the project, and you yourself put it into the project folder without telling the project that you did so, then just drag it into the project navigator to bring it to Xcode's attention. Note that you should decline Xcode's offer to make this part of the target. You don't want a .gitignore file to be built into your app; you just want the convenience of accessing it thru Xcode and the project window.