In order to add a ribbon button in Dynamics CRM on all entities, simply use the Application Ribbon in your solution, then edit it with the Ribbon Workbench. For more details, please read this article.
A Dynamics CRM Blog
In order to add a ribbon button in Dynamics CRM on all entities, simply use the Application Ribbon in your solution, then edit it with the Ribbon Workbench. For more details, please read this article.