title: can't run "hello world" python code in kivy launcher for android
body: <p>I'm trying to run this code from kivy.org in kivy launcher on my nexus 5.
  I've made a folder in kivy folder and "android.txt" file. Here's main.py:</p>
  
  <pre><code>import kivy
  kivy.require('1.9.0')
  from kivy.app import App
  from kivy.uix.label import Label
  
  
  class TestApp(App):
     def build(self):
            return Label(text='Hello World')
  if __name__ == '__main__':
     TestApp().run()
  </code></pre>
  
  <p>When i start it from launcher it crashes instantly.And this is what I get in logs folder:</p>
  
  <pre><code>[INFO              ] Logger: Record log in /storage/emulated/0/kivy/myshit/.kivy/logs/kivy_15-05-01_6.txt
  [INFO              ] Kivy: v1.9.0
  [INFO              ] Python: v2.7.2 (default, Apr  2 2015, 13:52:41) 
  [GCC 4.8]
  [INFO              ] Factory: 173 symbols loaded
  [WARNING           ] stderr: /data/data/org.kivy.pygame/files/lib/python2.7/site-packages/kivy/core/image/img_pygame.py:1.3: RuntimeWarning: import cdrom: No module named cdrom
  [WARNING           ] stderr: (ImportError: No module named cdrom)
  [INFO              ] Image: Providers: img_tex, img_dds, img_gif, img_pygame, img_pil (img_ffpyplayer ignored)
  [WARNING           ] stderr: Traceback (most recent call last):
  [WARNING           ] stderr:   File "main.py", line 9, in &lt;module&gt;
  [WARNING           ] stderr:     return Label(text='Hello World')
  [WARNING           ] stderr:   File "/home/tito/code/python-for-android/build/python-install/lib/python2.7/site-packages/kivy/app.py", line 798, in run
  [WARNING           ] stderr:   File "main.py", line 7, in build
  [WARNING           ] stderr:     class TestApp(App):
  [WARNING           ] stderr: NameError: global name 'Label' is not defined
  </code></pre>
  
  <p>Please guide me what do I do wrong?
  P.S. I don't compile app, I just wonna run it in launcher. Sample games and showcase work fine. </p>