Freshmvvm.FreshIOC.Container.Register<ICamera,Camera>();

public interface ICamera
{
   void TakePicture();
}

[assembly: Xamarin.Forms.Dependency (typeof (CameraImplementation))]
namespace yourapp
{
   // CameraImplementation class here
}

public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
        global::Xamarin.Forms.Forms.Init();

        InitIoc();

        LoadApplication(new App());

        return base.FinishedLaunching(app, options);
}

private void InitIoc()
{
        FreshMvvm.FreshIOC.Container.Register<IFileHelper, FileHelper>();
}

public class FileHelper : IFileHelper
{
    public string GetLocalFilePath(string filename)
    {
        string docFolder = Environment.GetFolderPath(Environment.SpecialFolder.Personal);

IFileHelper fileHelper = FreshMvvm.FreshIOC.Container.Resolve<IFileHelper>();
string dbPath = fileHelper.GetLocalFilePath("CoreSQLite.db3");

...