GridLayout:
    rows: 3
    Button:
        text: "Button 1"
        size_hint: None, None
        size: 100, 40
    Button:
        text: "Button 2"
        size_hint: None, None
        size: 100, 40
    Button:
        text: "Button 3"
        size_hint: None, None
        size: 100, 40
    Button:
        text: "Button 4"
        size_hint: None, None
        size: 100, 40
    Button:
        text: "Button 5"
        size_hint: None, None
        size: 100, 40
    Button:
        text: "Button 6"
        size_hint: None, None
        size: 100, 40