Particle Emitter is a component with a wide range of customization and variation options. It offers mouse-trail option, snap to stage-objects, can be used over existing objects and hooked up to any of your existing buttons. It comes with 4 predefined shapes (flares, bubbles, metal balls and valentine hearts) and you can add as many as you want. All movements, scaling, alpha transparencies and speed can be customized through Component Inspector.
Explanation of what parameters do on Included Readme file.