&gt; The critical function that none of the software I&#x27;m looking at can really do is putting a single sub-task from a story into a sprint.<p>The reason you&#x27;re not finding this function is that it&#x27;s in contradiction to agile&#x2F;scrum technique.  A sprint is a commitment to finish a set of stories in a time period.  It doesn&#x27;t make sense to take a sub-task of a story and put it into a sprint -- either you finished the work you committed to or you didn&#x27;t, and if not, you should let the fact that you weren&#x27;t able to finish it adjust your velocity for the next sprint.<p>You could make your story into an epic, and your sub-tasks into stories.<p>Pivotal Tracker (cloud-hosted), JIRA (cloud-hosted) and taiga.io (open source, self-hosted) are the best tools I&#x27;ve used.