The following is displayed when the plugin is enabled with Contact Form 7.
Strict Standards: Redefining already defined constructor for class Forms3rdPartyIntegration in /WORDPRESS/wp-content/plugins/forms-3rdparty-integration/forms-3rdparty-integration.php on line 95
Additionally it also displays this message in the Wordpress notification area
The plugin generated 248 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.
Tested using a clean WordPress 3.8.1 install running under MAMP.
closing as this is covered by Issue/Pull 7