Example VirtualRoleInitializer for EPiServer utilizing PlugInSettings

ApplicationSettings.cs

[GuiPlugIn(Area = PlugInArea.None, Description = "Web Application Settings")]
    public sealed class ApplicationSettings
    {
        private static ApplicationSettings instance;

        public ApplicationSettings()
        {
            PlugInSettings.SettingsChanged += UpdateVirtualRoles;
        }

        void UpdateVirtualRoles(object sender, EventArgs e)
        {
            VirtualRoleInitializer.RegisterVirtualRoles();
        }

        public static ApplicationSettings Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new ApplicationSettings();
                    PlugInSettings.AutoPopulate(instance);
                }

                return instance;
            }
        }

        [PlugInProperty(Description = "Awesome, necessary configuration", AdminControl = typeof(TextBox), AdminControlValue = "Text")]
        public string MyAwesomeConfigValue { get; set; }     
    }

VirtualRoleInitializer.cs

[InitializableModule]
[ModuleDependency((typeof(EPiServer.Web.InitializationModule)))]
public class VirtualRoleInitializer : IInitializableModule
{
    public void Initialize(InitializationEngine context)
    {
        RegisterVirtualRoles();
    }

    public static void RegisterVirtualRoles()
    {
        var virtualRoleRepository = VirtualRoleRepository<VirtualRoleProviderBase>.GetDefault();
        string role = virtualRoleRepository.GetAllRoles().FirstOrDefault(x => x.Contains(typeof(MyVirtualRoleType).Name));
        if(role != null)
            virtualRoleRepository.Unregister(role, true); // First, remove the role if it exists already. I don't want to have duplicate roles

        virtualRoleRepository.Register(typeof(MyVirtualRoleType).Name, new MyVirtualRoleType
            {
                SomeProperty = ApplicationSettings.Instance.MyAwesomeConfigValue
            });
    }

    public void Uninitialize(InitializationEngine context) { }
    public void Preload(string[] parameters) { }
}