DoToo.iOS

This is the iOS app. It contains a few more files than its Android counterpart:

The AppDelegate.cs file is the entry point for an iOS app. This file contains a method called FinishedLaunching(...), which is where we start writing code:

public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
    global::Xamarin.Forms.Forms.Init();
    LoadApplication(new App());
 return base.FinishedLaunching(app, options);
}

The code starts off by initializing Xamarin.Forms and then loads the application from the .NET Standard library. After that, it returns the control to iOS. It must do this within 17 seconds, or the app will be terminated by the OS.

The info.plist file is an iOS-specific file that contains information about the app, such as the bundle ID and its provisioning profiles. It has a graphical editor, but can also be edited in any text editor, since it's a standard XML file.

The Entitlements.plist file is also an iOS-specific file that configures the entitlements that we want our app to take advantage of, such as in-app purchases or push notifications.

As with the Android app's startup code, we don't need to understand what is going on here in detail, other than that it's important for the initialization of our app.