It's common to explicitly include open source code in iOS (or OS X) development. Cocoapods is a dependency manager that lets you track dependencies on 3rd party code, which in Cocoapods terminology, is known as pods, as well as update an Xcode workspace — which wraps around your Xcode project file – so all you need to do is the following:

1. Install cocoapods if you haven't:

   sudo gem install cocoapods

2. Create a Podfile in your Xcode project directory:

   pod init

3. Update the Podfile to list which pod(s) and version you would like to use:

   source 'https://github.com/CocoaPods/Specs.git' platform :ios, '8.0' use_frameworks!

   pod 'AFNetworking', '~> 2.5' pod 'ORStackView', '~> 2.0' pod 'SwiftyJSON', '~> 2.1'

4. Install the dependencies:

   pod install

5. Open the .workspace file instead of .xcodeproj file.

6. Import dependencies like this:

   import <AFNetworking/AFNetworking.h>

You then iterate through steps 3-6 during development and never use the .xcodeproj file again.

You can search for available pods at Cocoapods as well as for additional documentation.