I guess all will agree that every successful product is an outcome on number of iterations and to perform progressive iterations there has to be a way / tool which can be one language across the board. That's why these tools such as Sprint exists. And I am sure if you are a good manager ( a future self ), you would sure not giving yourself a suggestion of using "post-its, emails, spreadsheets, large whiteboards , hang a TV screen, pdfs" as the preferred way of managing iterations.