The following code illustrates how to make 'hello world' app in kivy.To run this app in ios and android save it as main.py and use buildozer.
from kivy.app import App
from kivy.uix.label import Label
from kivy.lang import Builder
Builder.load_string('''
<SimpleLabel>:
text: 'Hello World'
''')
class SimpleLabel(Label):
pass
class SampleApp(App):
def build(self):
return SimpleLabel()
if __name__ == "__main__":
SampleApp().run()