Needs patched Kivy. At least require 1.8.0-patched!

Author: alanjds

main.py

@@ -12,6 +12,8 @@
 from kivy.properties import StringProperty, BooleanProperty
 from kivy.app import App
 from kivy.clock import Clock
+import kivy
+kivy.require('1.8.0')
 
 from kivy.garden import navigationdrawer
 from kivy.uix.screenmanager import Screen