Smart Buttons are a new feature of the Ribbon Workbench 2016 allowing third party solution to be installed and publish a set of buttons that can be added by users to utilize features contained within the solution.
Usually, each envrionment (DEV/UAT/PROD) will have a different URL to call for a webhook. For this reason you can now place an Envrionment Variable in place of of a Url in the smartbutton configuration.
E.g. Web Hook Url: {%dev_somevariable%}
Read more at https://ribbonworkbench.uservoice.com/knowledgebase/articles/896958-smart-buttons