Sticky notes is a good approach to visualize the set targets, next steps, so far progress at a glance when we talk about project management.
They have designed the Whimsical Sticky Notes in a way that it has made this process more exciting and useful. Like on physical sticky notes you cannot add further subcategories without disturbing the overall board or you've to re-arrange it, but this is possible in Whimsical.
I hope this would be useful for developers too @lucdevent.