Thanks! I'm really happy to hear that since we tried to make drawing as user friendly as possible and spent some extra time on touch screen support. I had this vision in my mind where the discrete math lecturer would show a QR code (links to my website) on the screen and students would be able to fiddle with graphs and see all those things they learn interactively right there on their phone which.. could make the class more distracting or more engaging depending on how you look, but I liked the idea.