Case anyone stumbles on this about the best answer I've found so far is.
Xam.Plugins.Settings by James Montemagno
via: nuget
"Settings Plugin for Xamarin and Windows provides a consistent, cross platform settings plugin for Windows Phone Silverlight 8/8.1, Windows Phone 8.1, Windows Store, Xamarin.iOS, and Xamarin.Android when using a PCL or any project and is Xamarin.Forms and MvvmCross compatible. This makes it easier to create cross-platform .NET apps and have cross platform settings. Manage and use all settings from one PCL and save natively on each platform. *This plugin stores settings natively on each platform and does NOT save them to Json. This allows you to use native functionality such as PreferenceActivity on Android."