In this section, we will begin by applying for a Twitter Developer account, and then move on to creating and registering the TrackMyWalks application by creating an AppID within the Twitter Developer Portal that we can associate our app with. Doing this, we can then communicate with Twitter using the Twitter APIs.

Let's take a look at how we can achieve this by performing the following steps:

1. First, open your browser, type in https://developer.twitter.com/en/apply-for-access, and click on the Apply for a developer account button:

2. Next, you will be prompted to log into Twitter using your Twitter credentials. Once you have done that, you will be presented with the Account / Getting Started screen.
3. Then, click on the Create an app button that is located under the Getting Started heading, as shown in the following screenshot:

4. Next, click on the Create an app button located under the Create your first app heading within the Apps section, as shown in the following screenshot:

5. Then, enter Track My Walks as the name for our app in the App name (required) field, which will be displayed within the Twitter sign in page for our app.

6. Next, enter Track My Walks app to describe our app in the Application description (required) field. Also, provide a website URL to use for our app for the Website URL (required) field, as shown in the following screenshot:

7. Then, enter https://mobile.twitter.com/home in the Callback URLs field, which will be used to redirect the user to the page upon successfully signing into Twitter and your app.

8. Next, enter the name for your organization in the Organization name field (this field is completely optional). This is displayed within the Twitter sign-in page for your app, as shown in the following screenshot:

9. Then, you will need to provide a description to describe your application for the Tell us how this app will be used (required) field, as shown in the following screenshot:

10. Next, click on the Create button to display the Review our Developer Terms dialog, which you will need to adhere to, prior to your app being created, as shown in the following screenshot:

11. Finally, click on the Create button to proceed with the creation of your app. You will then be presented with the App Details section with details about the app you just created within the Twitter Developer Portal, as shown in the following screenshot:

Now that we have successfully applied for a Twitter developer account, as well as successfully created the Track My Walks App details within the Twitter Developer Portal, our next step is to take a look at what each of the relevant tabs contains and is used for, as shown in the following screenshot:

The Keys and tokens section contains important information that will allow our TrackMyWalks app to successfully communicate with our Track My Walks App ID, using the Consumer API keys for both our API Key and API secret Key. We will need to provide these for our RESTful Webservice when calling the Twitter API to allow our app to sign in, as can be seen in the preceding screenshot.

The Permissions section, contains important information pertaining to how the TrackMyWalks app will function. Within this screen, you can set different levels of access permissions that will affect how your application will function and communicate with Twitter through the use of the Twitter APIs.

Now that you have successfully created the TrackMyWalks application ID within the Twitter Developer Portal, our next step is to add the Xamarin.Auth NuGet package to our TrackMyWalks solution.