This small addition adds a warning message to the top of all ACP pages to show if you are on a production/production site or a development/test site.

You must specify the site type by going to ACP -> Settings -> Basic Settings. This setting is right below the forum header setting.

To change the text of your messages, you can change the phrases "ozzmodz_live_dev_site_dev" and "ozzmodz_live_dev_site_live."