System Center Configuration Manager (Current Branch) version 1802 was released yesterday. You can read the official announcement here and for a detailed list of what’s new, please see the following blog post. I blogged about how you can upgrade to 1802 here.
One of the changes related to Software Center , is that the Application Catalog will soon be unsupported and to encourage users to use the Software Center instead of the Application Catalog.
What is the Application Catalog
The Application Catalog (website) was introduced way back in 2012 so that users could request, search and install applications in a consistent way.
However, the functionality it provided has been migrated over time to the all new Software Center, and as a direct result of this support for the Application Catalog will be removed as of June 2018.
Thanks Johan Lindbergh for the graphic.