This effect creates several waves that move outward and fade. The trick is to make the waves fade you must insert a graphic (shape tween) into a movie clip (motion tween), then adjust the alpha of the last keyframe. Here is how you do it.
1. File > New> Modify> Movie> Background color > select black (you could choose any color)
2. Insert> New Symbol>Graphic>name it ripple
3. In keyframe #1 draw a small white ellipse over the central cross on the stage. Use the outline mode only with no fill color.
4. Insert a second keyframe in the timeline at position 30. Draw a large white ellipse.
5. Select the first keyframe, double click on it> In the Frame properties pop up box choose tweening tab> select shape tween. Play the movie and watch the circle expand.
6. Choose Edit>Edit movie to get out of symbol editing mode
7. Insert> New Symbol>Movie clip
8. Select Window>library to open the library window so the ripple graphic is visible
9. Select the first keyframe in the timeline and drag the ripple graphic onto the stage, center the graphic over the cross. You can use the magnifier and the arrow keys to position the graphic exactly over the central cross.
10. Create a 2nd keyframe at position 30 (same length of the first graphic animation), drag another instance of the ripple graphic onto the stage and center it over the cross.
11/ Select the first keyframe, double click to bring up the frame properties box>choose tweening tab> Select motion tween. You can play the movie to watch the circle move outward.
13. To make the ripple fade as it moves outward, Select the 2nd keyframe (#30), then select the Large graphic on stage (last frame of the first graphic movie) and double click on it to bring up the Instance properties box (or View>Instance Properties). Select the color effect tab>Choose Alpha> Adjust alpha to 2-5%. Now play the movie and the ripple graphic should fade as it moves outward.
13. To make several waves appear where one starts shortly after the other. Create a new layer, insert a new keyframe at position 2 in the time line. Drag the ripple graphic onto the stage and center. Insert a new keyframe at position 32, drag the ripple graphic on stage and center. Motion tween the layer and then select the graphic in the last keyframe and adjust alpha to 2- 5% as above. You can repeat this to again to add two more layers for a total of 4 layers When complete if the last frame is at 38 you can insert a new frame for each layer at position 4o. This allows the movie to complete but is not necessary. To get out of symbol editing choose Edit>Edit movie. You can then drag the movie clip onto your movie stage. To view the movie Select Control>Test movie.
If you wish to add a sound effect such as a water drop, you need to import the sound, open the ripple movie to edit it (double click on it in the library movie). In the symbol editing mode, open you library to view the sound icon. Select the first keyframe of layer on and drag the sound onto the stage. Edit>Edit Movie. The Control >Test movie to see and hear the effect. The screen shot shows you what your timeline window should like like in the edit symbol mode once you have added 4 layers and a Drip.wav sound file to the movie. You can use this procedure with variety of other geometric shapes.
Editable puddle with buttons movie in a zip file - download