In the previous chapter, you learned how to apply for a Twitter developer account so that you could incorporate social networking features by creating and registering our TrackMyWalks app within the Twitter Developer Portal. You then incorporated the Xamarin.Auth NuGet package within our solution and created a TwitterService Interface and Class that we can use to communicate with the Twitter APIs using RESTful web service calls. You created a TwitterSignInPage, as well as the associated TwitterSignInPageViewModel and TwitterSignInPageRenderer classes, so that users can sign into your app using their Twitter credentials.
Finally, you updated the WalksMainPage code-behind to call our TwitterSignInPage to check to see whether the user has signed in, as well as made changes to our WalkDistancePage XAML and code-behind so that we can utilize our...
