Save checkbox state android xamarin

I am new on xamarin and i am trying to save my checkbox state even if the app is closed because when i close it the checkbox reset to uncheck state...

also.. the image that was changed resets.. is there any way to preserve both?

 protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        SetContentView(Resource.Layout.layout1);

        var seletor = FindViewById<CheckBox>(Resource.Id.checkBox1);
        var imagem = FindViewById<ImageView>(Resource.Id.imageView1);

        seletor.Click += (o, e) => {
            if (seletor.Checked)
                imagem.SetImageResource(Resource.Drawable.estado1);

            else
                imagem.SetImageResource(Resource.Drawable.estado2);

        };
    }