One issue I've had with read-it-later apps is that I end up accumulating far too many articles and never actually reading them. Now my approach is simple: if I see something I want to read, I either read it immediately or never.
There could be a better system (for me): a read-it-later app with a strict limit—say, 3 or 5 slots. If it's full and you add a new article, the oldest one gets automatically deleted to make room. That way, you always have something to read, but never feel overwhelmed by an endless backlog.