Problem
In order to understand a paper better, someone suggested reading the commentary of a paper X first before actually reading the original paper. However, this seems to be a nontrivial task since there is no easy way to forward-track papers that cite one specific paper (i.e. paper X) while backward-tracking is straightforward.
More generally, is there tool/service that could build citation graph of a pool of papers, which might be one way to do both forward and backward tracking.