It would be quite interesting that the app added a little intelligence to tell the user how to classify what they read as soon as the need for that arises. Not trivial: it may be learning subtopics for a specialist, or a range of topics for someone who reads about many things, as well as accommodating for the profiles in between.
When I pin on Pinterest, the tool does a very good job in guessing which board I want to place that pin into. Something more sophisticated could be done with what we read here. Even adding some cool stats about collection contents – aimed at connecting the non obvious – would be a great plus.