Create's a 'bounce' animation as shown in the Google IO 2013 session 'A Moving Experience' (https://developers.google.com/events/io/sessions/326431311)

BouncyAndSquashyAndStretchyButtonActivity.java

/*
 <main.xml>

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/container"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:gravity="center_horizontal|top">

     <Button
     android:id="@+id/button"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:paddingLeft="16dp"
     android:paddingRight="16dp"
     android:text="Click Me!"/>
 </LinearLayout>
 */

public class MainActivity extends Activity implements View.OnClickListener {

    private static final long ANIM_DURATION = 300;
    private static final Interpolator DECEL_INTERPOLATOR = new DecelerateInterpolator();
    private static final Interpolator ACEL_INTER = new AccelerateInterpolator();

    private ViewGroup mContainer;

    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mContainer = (ViewGroup) findViewById(R.id.container);
        findViewById(R.id.button).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        final ObjectAnimator moveDownAnimator = getMoveDownAnimator(v);
        final ObjectAnimator stretchAnimator = getStretchAndSquashAnimator(v);
        final ObjectAnimator upAnimator = getUpAnimator(v);

        final AnimatorSet set = new AnimatorSet();
        set.playSequentially(moveDownAnimator, stretchAnimator, upAnimator);
        set.start();
    }

    private ObjectAnimator getUpAnimator(View v) {
        final PropertyValuesHolder pvhTY = PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, 0);

        final PropertyValuesHolder pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, 1f);
        final PropertyValuesHolder pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, 1f);

        ObjectAnimator upAnim = ObjectAnimator.ofPropertyValuesHolder(v, pvhTY, pvhSX, pvhSY);
        upAnim.setInterpolator(DECEL_INTERPOLATOR);
        upAnim.setDuration(ANIM_DURATION * 2);

        return upAnim;
    }

    private ObjectAnimator getStretchAndSquashAnimator(View v) {
        final PropertyValuesHolder pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, 1.5f);
        final PropertyValuesHolder pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, .5f);

        ObjectAnimator stretchAnim = ObjectAnimator.ofPropertyValuesHolder(v, pvhSX, pvhSY);
        stretchAnim.setRepeatCount(1);
        stretchAnim.setRepeatMode(ValueAnimator.REVERSE);
        stretchAnim.setInterpolator(DECEL_INTERPOLATOR);
        stretchAnim.setDuration(ANIM_DURATION);

        return stretchAnim;
    }

    private ObjectAnimator getMoveDownAnimator(View v) {
        final PropertyValuesHolder pvhTY = PropertyValuesHolder.ofFloat(View.TRANSLATION_Y,
                mContainer.getHeight() - v.getHeight());

        final PropertyValuesHolder pvhSX = PropertyValuesHolder.ofFloat(View.SCALE_X, .7f);
        final PropertyValuesHolder pvhSY = PropertyValuesHolder.ofFloat(View.SCALE_Y, 1.2f);

        ObjectAnimator downAnim = ObjectAnimator.ofPropertyValuesHolder(v, pvhTY, pvhSX, pvhSY);

        downAnim.setInterpolator(ACEL_INTER);
        downAnim.setDuration(ANIM_DURATION * 2);

        return downAnim;
    }
}