The clincher, the thing that made Quick Key go viral, was a poorly-lit video of an excitable guy holding his iPhone up to a Scantron page, one of those test pages you used to fill out in school. He thumbs through page after page, making comments on students’ performance as the app scans the page and instantly reports a grade. The video was amazingly compelling. The creator, Walter O. Duncan IV, can barely contain his excitement. His app looked great, it worked seamlessly, and the video struck a nerve with students and teachers, pocketing 260,000 views on YouTube and popping up on the front page of Reddit.