Kids who are changing the world

"Have you ever wondered what you could do to change the world? Find out how kids are helping the environment, inventing . . . medical devices, aiding the homeless, designing apps so other kids won't ever have to eat alone in the cafeteria, and more! Learn all about what they've come up with and how their ideas are changing lives in this story of four . . . kids everyone should meet!"--Provided by publisher.