y = ['text', 'new screen', 'twelve']
sm = ScreenManager()
screens = [Screen(name=i) for i in y]
for i in range(0, 2):
    sm.add_widget(screens[i])
screens[0].add_widget(Button(text='Test', size_hint_x=None, width=100))
# screens[1].add_widget(Button(text='Worked!'))
screens[1].layout = GridLayout # Doesn't work