James Proud, founder and CEO of Hello, wants to make sure you get a good night's sleep. The 25-year-old wunderkind has built a company valued at about $250 million around a voice-activated device called Sense. About the size of a tennis ball, Sense is placed on your bedside table, and works with a quarter-sized tracking pill that clips to your pillow. "It's your alarm clock. It's meditative sounds to help you fall asleep like rainfall and white noise. But it's also tracking your sleep," Proud told CNBC's "Squawk Box" on Friday.

"All these sensors are looking at everything in the environment, light sound, temperature. All of the things that affect your sleep, humidity as well," explained Proud, who said he taught himself to code when he was 9 years old. Sense can also connect to smart home thermostats to automatically adjust temperatures as you sleep and wake up, he added. "It's [as] if you have something on your wrist, but instead it's on the pillow," he explained. "When you put your head on your pillow, it starts tracking." Proud, who appeared on the January 2017 cover of Forbes, was part of the inaugural class of The Thiel Fellowship.