The feaure itself is to show the recently launched applications and recently used documents.
This is not activated by default, but it is easy to turn on, and will boost the productivity for sure.
You can enable it by editing the preferences of the menu, by right click on it, and choosing 'Preferences'.
At the Plugins tab, enable 'Show recent documents plugin':
Whenever you launch an application from the menu, or open a document, that item will be placed at the top of the list.
Please note: the launched application in only tracked when starting it from the menu. For other places like desktop icons, it will not be registered.
May the Force be with you,