3 PRO is an iPhone app developed by 3Plus International Inc. It falls under the category of Lifestyle, specifically Health & Fitness. With 3 PRO, you can easily track your daily activity, set personalized goals, and monitor your health information.

The app provides activity tracking features that allow you to monitor your daily steps taken, distance traveled, calories burned, and more. This gives you a comprehensive view of your physical activity throughout the day. Additionally, you can set personalized goals for steps, calories, distance, active minutes, and sleep based on your activity level, helping you reach your target fitness level.

One of the standout features of 3 PRO is its heart rate monitor. Whether you want to maintain your heart rate level during workouts or measure your resting heart rate to track your fitness progress, this app has you covered. It also offers smart notifications, allowing you to receive and read a variety of notifications directly on your watch.

Another useful feature is the weather app, which lets you check today's weather without needing to switch to another app. All your health information can be synchronized to HealthKit, making it easy to integrate with other health and fitness apps.

Overall, 3 PRO is a comprehensive health and fitness tracker that offers a range of features to help you monitor your activity, set goals, and track your progress.