So, how to make this available to the normal users, you ask? Easy - make it available to the normal file managers via KIO - just type activities:/ in Dolphin, Konqueror or the Folder View applet, and you’ll get a list of all activities, and files that belong to them.

You can see what it looks like in the screenshots. At the moment, it is a bit buggy, but it will work as expected for SC 4.9.