Cal AI, a calorie-counting app created by 18-year-olds Zach Yadegari and Henry Langmack, has surpassed 5 million downloads in just eight months. The app offers users the ability to photograph their food for automated calorie and macro logging, resulting in over $2 million in revenue last month. Despite competing with established apps like MyFitnessPal, Cal AI boasts a 4.8-star rating on both Apple and Google Play stores. The founders emphasize their use of advanced AI models, achieving a 90% accuracy in food recognition. They plan to continue their education while managing their growing startup.