grails create-plugin simple
create-plugin command creates a Grails plugin project.
Creates a Grails plugin project. A Grails plugin project is just like an application project except it contains a plugin descriptor and can be packaged as a plugin and installed into other applications.
Plugins are not just useful for plugin developers, but also as a way to modularize large Grails applications. Refer to the section on Plugin Development in the user guide for more information on developing plugins for Grails.
grails create-plugin <<name>>