from kivy.uix.button import Button
from kivy.app import App
from kivy.animation import Animation

class TestApp(App):
    def animate(self, instance):
        animation = Animation(pos=(100, 100), t='out_bounce')
        animation += Animation(pos=(200, 100), t='out_bounce')
        animation &= Animation(size=(500, 500))
        animation += Animation(size=(100, 50))
        animation.start(instance)

    def build(self):
        button = Button(size_hint=(None, None), label='plop')
        button.bind(on_press=self.animate)
        return button

TestApp().run()