A simple Swift class to prompt user to rate app at launch.
Simply drag the RatingManager.swift file into your Xcode project and put that code in your App Delegate:
let ratingManager = RatingManager(controller: self.window!.rootViewController, link: "https://itunes.apple.com/fr/app/your-app-link")
window!.makeKeyAndVisible()
ratingManager.promptAlert()
The RatingManager class is fully documented.
If you want to change the prompt period, edit the period method in your App Delegate.
At this time, strings are in french but if someone wants to translate into english or other language you can create a Pull Request, so I will add it to my repo.