Immediately after installing you can assign multiple categories to articles in edit article mode and you will see each article in the relevant sections.
However! Now my latest articles module isn't working correctly - showing only articles from one category out of the five selected from the module menu. Upon noticing this I tried to contact/email support with no reply whatsoever. Their forum is completely dead. Posting on there was a waste of time.
I noticed why the problem is occurring and feel it could cause a load of problems in future. As for me, I'm not going to use this. Quite dissatisfied.