An after-school skateboarding program, an online platform connecting excess goods with social shoppers, and an app that diagnoses epilepsy syndromes were the big company winners Thursday night at Seed Spot’s third Demo Day.

Nine local social entrepreneurs were each given three minutes to talk about their businesses in front of a live audience of more than 850 at the Orpheum Theatre.

The event is the culmination of Seed Spot’s 16-week program offering business curriculum, mentoring, office space and legal advice to help the entrepreneurs with their ventures.

“We believe it is possible to grow game-changing solutions to significant social problems here in Phoenix, and the third class of Seed Spot ventures did not disappoint last night,” Seed Spot co-founder and CEO Courtney Klein said in an email. “The third class of Seed Spot entrepreneurs worked incredibly hard over the past four months to validate their business models, test their solutions in the market and commit themselves to solving social problems.”

Skate After School was one of the biggest winners, receiving $15,000 from the Arizona Community Foundation’s Pakis Center for Business Philanthropy. The nonprofit skateboarding program partners volunteers with kids in low-income areas of greater Phoenix who take care of themselves after school.