Yes. When you installed the component, the search plugin was automatically installed and enabled. If you upgraded and had previously turned off the plugin, it will remain disabled.

The 'Searchable Fields' panel in configuration tells the plugin which fields in Grumpy Contacts to search. Custom fields are not available for searching at this time.

If the 'Use Search Areas' option of the search menu is turned on (this is the  default), you will see an area called 'Grumpy Contacts'. You can change this text in the plugin manager. Look for 'Search - Grumpy Contacts' among the search plugins and edit its parameters to suit your needs.