OctoPocus, is a dynamic guide that combines on-screen feedforward and feedback to help users learn, execute and remember gesture sets. OctoPocus can be applied to a wide range of single-stroke gestures and recognition algorithms and helps users progress smoothly from novice to expert performance. Two experiments show that OctoPocus is significantly faster and improves learning of arbitrary gestures, compared to conventional Help menus. It can be adapted to a mark-based gesture set, significantly improving input time compared to a two-level, four-item Hierarchical Marking menu.
for more info. : lri.fr/~bau/files/uist2008op.pdf