react-native: [iOS] Integrating into existing app: RCTJSCWrapper.h 'string' file not found

I’m attempting to integrate a React Native component into an existing Swift app. I am following the instructions here: https://facebook.github.io/react-native/docs/embedded-app-ios.html

1. The documentation is unclear on the steps to bridge the RN view to the Swift app. It says to create a ReactView.h, and then a ViewController.m, and then goes on to say “For Swift apps there is no need for that.” No need for what - the ViewController.m, the ReactView.h, or both??? Very poor wording.
2. Either way, when I create a ReactView.swift file:

import UIKit
import React

class ReactView: UIView {

  let rootView: RCTRootView = RCTRootView(bundleURL: NSURL(string: "http://localhost:8081/index.ios.bundle?platform=ios"),
    moduleName: "SimpleApp", initialProperties: nil, launchOptions: nil)

  override func layoutSubviews() {
    super.layoutSubviews()

    loadReact()
  }

  func loadReact () {
        addSubview(rootView)
        rootView.frame = self.bounds
  }
}

And import it into a View in Xcode, when I build the project I get the following error:

RCTJSCWrapper.h: 'string' file not found ReactView.swift: Could not build Objective-C module 'React'