I implemented the StoriesAPI (from the appstore) in my application and now I'm able to get relevant information from the SprintR development portal to my app. This works like a charm! And it's nice to work with app services. However, in SprintR we use Sprints -> Stories -> Tasks -> Subtasks (possibly multiple levels). I can get all this info, except for the subtasks. Is there something I'm missing? Addition: I can get subtasks manually using the task ID as seen in Sprintr.
The GetTask operation requires a story id as input for this microflow I think you should be able to pass in a task Id, and get all sub tasks from the task you passed into this microlfow. Just keep doing that recursively until there are no subtasks returned.