main.py

from kivy.app import App
from kivy.lang import Builder
from jnius import autoclass
from kivy.properties import BooleanProperty

Context = autoclass('org.renpy.android.PythonActivity')
context = Context.mActivity
vibrator = context.getSystemService(Context.VIBRATOR_SERVICE)


kv = '''
FloatLayout:
    Button:
        size_hint: .4, .1
        pos_hint: {'center_x': .5, 'top': .1}
        on_press: app.feedback()
        text: 'touch me'

    Button:
        size_hint: .3, .3
        pos_hint: {'center_x': .5, 'y': .3}
        on_touch_down: args[1].ud['inside'] = self.collide_point(*args[1].pos)
        on_touch_move: app.limit_feedback(self, args[1])
        text: 'enter/leave me'
'''


class HapticApp(App):
    inside = BooleanProperty(False)

    def build(self):
        return Builder.load_string(kv)

    def feedback(self):
        vibrator.vibrate(10)
        print "vibrate?"

    def limit_feedback(self, button, touch):
        ud = touch.ud
        collide = button.collide_point(*touch.pos)
        if ud['inside'] != collide:
            self.feedback()

        ud['inside'] = collide


if __name__ == '__main__':
    HapticApp().run()