1 Minute gestures (special tool)

Done as part of a practice session with poses of 60 seconds in length with my Atcatel tablet on Autodesk Sketchbook. After a few gestures I decided to use a particular tool that will help me achieve more fluid strokes and better proportions. Can you guess which ones I use this tool and what I used? My current goal is: Improve at correctly capturing the overall proportions of the human form