To build and run CastrApp on iOS, we use CocoaPods to manage packages and dependencies.
To install CocoaPods, you need Ruby on your computer. Ruby is integrated by default in macOS. You can install Ruby with the next command:
$ sudo apt-get install ruby-full
After this, just run:
$ sudo gem install cocoapods
To run properly the project, you need to install Pods in your Xcode App WorkSpace. Shut down Xcode, open Terminal and go into your project file with:
$ cd your-project-path/
And run the cocoapods installer:
$ pod install
Cocoapods will install all the packages declared in the file Podfile. After that, you need to reopen your project with the file CastrApp.xcodeworkspace. Build the app using Cmd+B. That's it !