diff --git a/android/AndroidOpenGLESLessons/default.properties b/android/AndroidOpenGLESLessons/project.properties
similarity index 80%
rename from android/AndroidOpenGLESLessons/default.properties
rename to android/AndroidOpenGLESLessons/project.properties
index e2e8061..ea89160 100644
--- a/android/AndroidOpenGLESLessons/default.properties
+++ b/android/AndroidOpenGLESLessons/project.properties
@@ -4,7 +4,7 @@
 # This file must be checked in Version Control Systems.
 #
 # To customize properties used by the Ant build system use,
-# "build.properties", and override values to adapt the script to your
+# "ant.properties", and override values to adapt the script to your
 # project structure.
 
 # Project target.
diff --git a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson5/LessonFiveRenderer.java b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson5/LessonFiveRenderer.java
index d2f57d5..ab0fec6 100644
--- a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson5/LessonFiveRenderer.java
+++ b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson5/LessonFiveRenderer.java
@@ -11,7 +11,6 @@
 import android.opengl.GLES20;
 import android.opengl.GLSurfaceView;
 import android.opengl.Matrix;
-import android.os.Handler;
 import android.os.SystemClock;
 
 import com.learnopengles.android.R;
diff --git a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixActivity.java b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixActivity.java
index 0ea7122..931304d 100644
--- a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixActivity.java
+++ b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixActivity.java
@@ -12,7 +12,6 @@
 import android.util.DisplayMetrics;
 import android.view.View;
 import android.view.View.OnClickListener;
-import android.widget.Toast;
 
 import com.learnopengles.android.R;
 
diff --git a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixGLSurfaceView.java b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixGLSurfaceView.java
index 2d0bf4e..dce83d0 100644
--- a/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixGLSurfaceView.java
+++ b/android/AndroidOpenGLESLessons/src/com/learnopengles/android/lesson6/LessonSixGLSurfaceView.java
@@ -3,7 +3,6 @@
 import android.content.Context;
 import android.opengl.GLSurfaceView;
 import android.util.AttributeSet;
-import android.util.FloatMath;
 import android.view.MotionEvent;
 
 public class LessonSixGLSurfaceView extends GLSurfaceView