An extension of FloatingActionButton with a simple show/hide animation.

AnimatedFloatingActionButton.java

/**
 * Copyright 2015 Karl Lindmark <karl@ninetwozero.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class AnimatedFloatingActionButton extends FloatingActionButton {
    private static final float MIN_SCALE = 0.0f;
    private static final float MAX_SCALE = 1.0f;
    private static final float ROTATION_OFFSET = 90;
    private static final long START_DELAY = 400L;
    private static final long ANIMATION_DURATION = 300L;

    public AnimatedFloatingActionButton(Context context) {
        super(context);
    }

    public AnimatedFloatingActionButton(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public AnimatedFloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void showWithAnimation() {
        // Make sure the relevant values are "reset"
        setRotation(-ROTATION_OFFSET);
        setScaleX(MIN_SCALE);
        setScaleY(MIN_SCALE);

        animate().scaleX(MAX_SCALE)
                .scaleY(MAX_SCALE)
                .rotationBy(ROTATION_OFFSET)
                .setStartDelay(START_DELAY)
                .setDuration(ANIMATION_DURATION)
                .start();
    }

    public void hideWithAnimation() {
        animate().scaleX(MIN_SCALE)
                .scaleY(MIN_SCALE)
                .rotationBy(-ROTATION_OFFSET)
                .setDuration(ANIMATION_DURATION)
                .start();
    }
}