How does the collab work here. I'm coming from iscribble. Do you draw the pic then somehow send it to the user you want to collab with, or are you able to draw at the same time on the canvas?

the first way...though you can draw together on the live 2draw thingy

just choose collab board when you start drawing then after you drew and submited, go down to the drawing options and hit "modify users". Search who you want to add, and add them.