diff --git a/README.rst b/README.rst
index a02ec19a7..8498806ba 100644
--- a/README.rst
+++ b/README.rst
@@ -26,7 +26,7 @@ GPS                                X             X             X
 Notifications                      X             X                 X       X   X
 Text to speech                     X             X             X   X       X   X
 Email (open mail client)                         X             X   X       X   X
-Vibrator                                         X
+Vibrator                           X             X
 Sms (send messages)                X             X
 Compass                            X             X             X
 Unique ID (IMEI or SN)             X             X             X   X       X   X
diff --git a/examples/vibrator/main.py b/examples/vibrator/main.py
index 3644b4e93..d7b0f30d6 100644
--- a/examples/vibrator/main.py
+++ b/examples/vibrator/main.py
@@ -1,8 +1,6 @@
-
 from kivy.app import App
-from kivy.uix.boxlayout import BoxLayout
 from kivy.lang import Builder
-
+from kivy.uix.boxlayout import BoxLayout
 
 Builder.load_string('''
 #:import vibrator plyer.vibrator
@@ -36,10 +34,12 @@
 
 
 class VibrationInterface(BoxLayout):
+    '''Root Widget.'''
     pass
 
 
 class VibrationApp(App):
+
     def build(self):
         return VibrationInterface()
 
diff --git a/plyer/facades.py b/plyer/facades.py
index 10ec41038..e8a948531 100644
--- a/plyer/facades.py
+++ b/plyer/facades.py
@@ -251,7 +251,7 @@ def vibrate(self, time=1):
     def _vibrate(self, **kwargs):
         raise NotImplementedError()
 
-    def pattern(self, pattern=[0, 1], repeat=-1):
+    def pattern(self, pattern=(0, 1), repeat=-1):
         '''Ask the vibrator to vibrate with the given pattern, with an
         optional repeat.
 
diff --git a/plyer/platforms/android/vibrator.py b/plyer/platforms/android/vibrator.py
index 4642957ea..c28fe8e21 100644
--- a/plyer/platforms/android/vibrator.py
+++ b/plyer/platforms/android/vibrator.py
@@ -1,12 +1,24 @@
+'''Implementation Vibrator for Android.'''
+
 from jnius import autoclass
 from plyer.facades import Vibrator
 from plyer.platforms.android import activity
+from plyer.platforms.android import SDK_INT
 
 Context = autoclass('android.content.Context')
 vibrator = activity.getSystemService(Context.VIBRATOR_SERVICE)
 
 
 class AndroidVibrator(Vibrator):
+    '''Android Vibrator class.
+
+    Supported features:
+        * vibrate for some period of time.
+        * vibrate from given pattern.
+        * cancel vibration.
+        * check whether Vibrator exists.
+    '''
+
     def _vibrate(self, time=None, **kwargs):
         if vibrator:
             vibrator.vibrate(int(1000 * time))
@@ -18,11 +30,19 @@ def _pattern(self, pattern=None, repeat=None, **kwargs):
             vibrator.vibrate(pattern, repeat)
 
     def _exists(self, **kwargs):
-        return vibrator.hasVibrator()
+        if SDK_INT >= 11:
+            return vibrator.hasVibrator()
+        elif activity.getSystemService(Context.VIBRATOR_SERVICE) is None:
+            raise NotImplementedError()
+        return True
 
     def _cancel(self, **kwargs):
         vibrator.cancel()
 
 
 def instance():
+    '''Returns Vibrator with android features.
+
+    :return: instance of class AndroidVibrator
+    '''
     return AndroidVibrator()