react-native link to work out of the box on iOS, you need to be using Pods to manage dependencies. Please also remember to run pod install after the link step. Depending on your project, you may also need use_frameworks! in your Podfile. If using Pods causes a problem for your project, you may use Carthage to manage your Cobrowse.io dependencies, or you may also add the frameworks to your project by hand. More info at iOS SDK Installation.