It's time to start building the app. Create a new blank Xamarin.Forms app using .NET Standard as the Code Sharing Strategy and select iOS, Android, and Windows (UWP) as the platforms. We will name the project Weather.
As the data source for this app, we will use an external weather API. This project will use OpenWeatherMap, a service that offers a couple of free APIs. You can find this service at https://openweathermap.org/api. We will use the 5 day / 3 hour forecast service in this project, which provides a 5-day forecast in 3-hour intervals. To use the OpenWeather API, we have to create an account to get an API key. If you don't want to create an API key, you can mock the data instead.
Creating models for the weather data
Before we write the code to fetch data from the external weather service, we will create models in order to deserialize the results from the service. We will do this so that we have a common model that we can use to return data from...