One day before Apple CEO Tim Cook takes the stage at the company's annual World Wide Developer Conference, Apple's top executive mingled with a much smaller gathering of developers inside the Steve Jobs Theatre.

Unlike the typical developer conference crowd, this crowd of 350 consisted mainly of teenagers who balance app development with homework, studying, and applying for college. The group were recipients of Apple's WWDC scholarships, a program that gives students and members of STEM organizations from around the world the opportunity to attend Apple's developer conference.

This year, many of those scholarships went to budding developers hoping to make an impact in health, education, and environmental issues. Among them, six young app makers got the opportunity to sit down with Lisa Jackson, Apple's vice president of environment, policy, and social initiatives, to talk about their experiences and the challenges they still face.

"You're the epitome of what Apple thinks of for the App Store, this marketplace of ideas and tools," Jackson told the group.

A quick look at their collective accomplishments, and it's not difficult to understand why Apple's keen to highlight their contributions.

• James Dale, 17, who developed a game meant to educate people about the dangers of air pollution. He also mentors other students learning to code at his school in Melbourne.

• Akshaya Dinesh, 18, who created a nonprofit called Girls Make apps that aims to help close the gender gap in the tech industry with educational programs for young girls.

• Leonardo Alves de Melo, 23, who created a game called "Save the Trees" to raise awareness around deforestation of rainforests in Brazil.

• Varun Shenoy, 16, who was awarded the scholarship for a project meant to help get kids get excited about recycling. He also created an app called BioSnap, which uses machine learning to make it easier for people to track medical data.

• Amanda Southworth, 16, who dropped out of high school to work full-time on her nonprofit software development company Astra Labs. She's created apps to help people with anxiety and a safety app for LGBTQ youth.

• John Wahlig, 16, who created a project that "explores the possibilities for iPad to help kids with Down Syndrome and other learning disabilities." He also created an iOS app to help coaches diagnose concussions from the sidelines.

Though Apple's put on the scholarship program for years, this year's WWDC comes at a crucial moment for the tech industry, which is grappling with issues like privacy and wellbeing. At WWDC, Apple is expected to follow Google and other companies with features dedicated to reducing the addictive properties of our iPhones, for example.

But though many of the student developers are working to solve problems that aren't always top of mind for Silicon Valley, they say they see themselves as part of something bigger.

"As young people we have such a fresh perspective on these ideas," Dinesh said. "We're very, very passionate about the problems that we see in our communities."