In addition to traditional add-ins, ArcGIS Pro SDK configurations are another customization pattern and a powerful way of extending ArcGIS Pro. Configurations are essentially built in the same way as add-ins, using a Pro SDK project template. Controls and other traditional add-in functionality can be included as well. Configurations are unique in that they allow you to develop and include:
• Solution branding of the Pro UI – you can create a highly customized UI and start-up user experience for Pro, with a custom product splash screen, a custom start page, and your own application icon
• Conditional or role-based customization – you can build logic into the Pro start-up experience and tailor the Pro UI ribbon based on your own conditional logic, logins, ArcGIS Online organization roles, and more
• Control how and which add-ins are loaded into Pro, providing even more control
Learn more about the ArcGIS Pro SDK and developing add-ins and configurations for Pro at: http://pro.arcgis.com/en/pro-app/sdk/