gistfile1.py

<MyScreenManager>:
    MainMenuScreen:

<MainMenuScreen>:
    name: 'MainMenuScreen'
    ScrollView:
        size_hint_x: None
        width: root.width 
        effect_cls: 'ScrollEffect'
        bar_width: 10
        bar_color: 0.6,0.6,0.6,1

        BoxLayout:
            canvas.before:
                Color:
                    rgba: 0,0.2,0.5,0.6
                Rectangle:
                    pos: self.pos
                    size: self.size
            size_hint_x: None
            width: root.width * 2
            orientation: 'horizontal'
            BoxLayout:
                orientation: 'vertical'
                size_hint_x: None
                width: self.parent.width / 2
                pos: self.parent.width / 2, 0
                Button:
                    size_hint_x: None
                    width: self.parent.width
                Button:
                    size_hint_x: None
                    width: self.parent.width
                Button:
                    size_hint_x: None
                    width: self.parent.width
                Button:
                    size_hint_x: None
                    width: self.parent.width