Our solutions can come with one or multiple Add-ins. When you buy the solution, you will have the right to use any of the included Add-ins. We do not sell Add-ins separately. So, for instance, you can not purchase the 'Content Chooser for Outlook' Add-in without also purchasing the 'Content Chooser for Office' Add-in that the same time. But once you purchased the 'Content Chooser' solution, you can, of course, opt only to install specific Apps or Add-ins that come along with the 'Content Chooser' solution.Please note: the officeatwork 'Admin Center' is free and requires no purchasing. The 'Admin Center' is for configuring your experiences in the different Apps and Add-ins across all officeatwork solutions.