This as-told-to essay is based on a conversation with Zach Yadegari, an 18-year-old cofounder and CEO at Cal AI, an AI-powered nutrition and food tracking app, based in Miami. Business Insider has verified the financial claims mentioned in this article. This story has been edited for length and clarity. I sold my first app at 16 years old for almost $100,000. It was called Totally Science, an unblocked gaming website that allowed students to play games in school. It earned me thousands a year