Are there no more classes as files in Swift?

From all of the tutorials on this site and others (particularly those to do with Sprite Kit which is where my interest lies) nobody appears to be creating, for instance, Sprite Nodes by adding a new file, they just seem to be declaring them in the code.

The reason I ask is I have a program I've been working on for a while in Objective-C but, as it is not finished, I would like to recreate it in Swift, and continue development. It's very confusing as the whole way in which files are imported into each other has changed, and I'm wondering if my nicely organised classes are now all for naught.

In fact, I'm having difficulty just getting an app to get past the pre-set title sheet that, unhelpfully, appears by default at the start of a SpriteKit game. It would be great if there was a post on what is different about starting a game in Xcode 6 as opposed to Xcode 5, it seems like some of the ViewController and App Delegate code has changed.

Any suggestions, and especially more tutorials about Sprite Kit with Swift would be fabulous. It would be great to see Space Cat made in Swift, to give us Sprite Kit learners a translation foundation with something we're already familiar with. Or even better something that show us how to use the Level Builder! :)

Cheers, James

BTW: There is no "Swift" in the options for Topics in the forum or in the dropdown menu at the bottom of this message form.