How to store App settings in Xamarin.Forms

It can be done this way too using Properties Dictionary

for storing data:

Application.Current.Properties ["id"] = someClass.ID;

for fetching data:

if (Application.Current.Properties.ContainsKey("id"))
{
    var id = Application.Current.Properties ["id"] as int;
    // do something with id
}

ref: https://developer.xamarin.com/guides/xamarin-forms/working-with/application-class/#Properties_Dictionary

The Application object (in VS you get an App class that inherits from it, I think the Xamarin Studio template might be slightly different) has a Properties dictionary that is specifically for this. If you need to make sure your properties get saved right away, there is a Application.SavePropertiesAsync method you can call.