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