Cardiio: Heart Rate Monitor is a free iPhone app developed by Cardiio Inc., falling under the Lifestyle category with a focus on Health & Fitness. The app allows users to measure their heart rate using their phone's camera, gain insight into their fitness levels, perform quick high-intensity workouts, and track their progress effectively. Featured on The Doctors (CBS) and ABC News, Cardiio offers a user-friendly interface for monitoring heart rate effortlessly.

By simply covering the back camera with a finger, users can measure their pulse instantly. Additionally, the app provides insights into how heart rate correlates with overall fitness and offers built-in high-intensity circuit training exercises that take only 7 minutes to complete, aiding users in their fitness journey.