One app would help subway riders stay awake on their long commutes, while another would alert emergency contacts if they didn't feel safe walking home. 

Those were just two of the ideas for proposed apps pitched by teenage girls from city high schools to Uber CEO Travis Kalanick at an event in Manhattan this past week. 

"We admire women engineers," Kalanick said, wearing a "Lady eng" shirt.

The teenagers are members of the tech group Girls Who Code, and the practice pitch came after a summer-long training. 

"It's great practice for the girls to be able to articulate a big vision to a CEO and entrepreneur and get feedback," said Reshma Saujani, who founded the tech group.

Kalanick gave the girls feedback on their ideas, such as urging creators of a textbook app to disrupt the industry by trying to get around copyright laws. His app company has been shaking up and decimating the taxi industry in cities across the world, including in New York City. 
  
Last year, teens in "Girls Who Code" came up with a video feminist game called Tampon Run to take the stigma out around menstruation. The game garnered significant attention from the press.