2. Dave Morin

CEO of Path

Path is the one app that keeps Facebook worried, though you might never guess it from talking to CEO Dave Morin. Very direct and to the point, he is laser-focused on building the perfect experience for his users — not killing Facebook.

Path, which is basically a virtual diary that you share with your closest friends, has a beautiful interface that's far more intuitive than Facebook's mobile app. Thanks to the work of Morin and his team of 40 developers and designers.

1. Daniel Gross

CEO of Cue

Gross is Y Combinator’s first Israeli entrepreneur who joined the incubator when he was just 18. He started the company right out of high school. The first company didn't go too well, but since starting Greplin, he's become one of the hottest CEOs in the valley. Being one of the youngest founders in Silicon Valley hasn't held him back much.