This module creates a button called "Clear Varnish page cache" in the shortcut-set-1 toolbar.
When clicking the button, Varnish will receive the command to purge the cache for the page that the user is viewing at that time.
Why was this module created ?
In high traffic sites, it gets really expensive to do a "drush cc all" call every time a content editor wants to update an article, block, etc. Therefor, this little module comes to the rescue.