David Lieb knew his company Bump was going to take off when strangers dressed up as the app for Halloween. While at the University of Chicago, he built the app so he could more easily exchange contact information with new classmates by physically bumping their phones together. Bump was no blip. The app exploded. It was downloaded 150 million times and hit #2 in the App Store. Apple even featured Bump in a commercial that aired on prime-time television.
