The Multisite Administration Tools plugin adds additional columns to the Sites, Plugins and Themes tables in the Network Admin interface.
On the Sites table, two additional columns are added to allow admins to easily view the theme of the site, and also any plugins that are enabled.
On the Themes table, there is an additional column added which allows the administrator to see all sites that are actively using that theme.
On the Plugins table, there is an additional column added which allows the administrator to see all sites that are actively using that plugin.