Extensions are installable packages which give CiviCRM new functionality, and this directory provides a centralized list of extensions which the CiviCRM community has created. This listing displays CiviCRM extensions that work on all Content Management Systems (CMS).
If you don't, enable this extension that will add the missing stylesheets so the default datavisualisations look better
When a customer buys something from a Drupal Commerce online shop, this module:
Creates a CiviCRM contact record if the purchaser doesn't already exist.
Adds the purchaser to the specified CiviCRM group.
Adds (or updates) a contribution history to their record.