Re the problem we are trying to solve: giving feedback on documents really sucks. Emailing around 'Slide 1: change x,y,z, Slide 2: change this' and other out-of-context comments is a massive pain-point for users, who want to be able to do it quickly, visually, and in their browser (instead of in an old piece of desktop software). Feel free to ping me on leo@kivo.com if you have any more questions.