My Apple Watch project is in Swift. I have used CocoaPods to install MMWormhole, and I created the bridging header as described in these links: http://bencoding.com/2015/04/15/adding-a-swift-bridge-header-manually/ How to call Objective-C code from Swift When I created the bridging header, I target it to my iphone app, and also watch Extension. The bridging header.h, I have this: #import "MMWormhole.h" In my iPhone app View Controller, I have this: import UIKit import Foundation let wormhole = MMWormhole(applicationGroupIdentifier: "group.cocoShareData", optionalDirectory: "wormhole") and