Value Converters
Value Converters form an important concept in data-binding because they allow you to customize the appearance of a data property at the time of binding. If you have done any WPF or Windows app development, you are probably familiar with how Value Converters work. Xamarin.Forms provides an almost identical Value Converter interface as part of its API.
One of the biggest benefits to a Value Converter is that it prevents you from having to add a bunch of getter properties to your data model to adjust how things are displayed. For example, imagine you had a status property on your model and you wanted to change the font color of the status when it is displayed based on its value. You could add a getter property to your model that returns a color based on the current value of the status property. This approach works, but it clutters the model and also potentially leaks platform-specific and user interface logic into the model, which should typically remain very lean and agnostic...