E-cigarette company Juul is working on a Bluetooth-connected version of its popular device, and its features could help the company combat underage use. Valued at $15 billion, Juul claims over 70 percent of the US e-cigarette market, and it has been working to expand internationally. But as it continues to attract investment and users, the company is also admitting that its product is being used by teenagers. "We acknowledge kids are using the products," Juul Chief Administrative Officer Ashley Gould said earlier this year. "We're committed to stopping it."