Customizing SparkWeb

Hi,

I am new to Spark development on Openfire.

Is it possible to develop plugins to extend functionality of SparkWeb or is that just possible for Spark IM Client (Swing Client) ?

If yes, any simple example to add a new contact group/contact item programatically in Spark Web client ?

Also, Where do the custom jar files have to be put for extending functionality for SparkWeb running on Openfire ?

Thanks