What are the most popular fitness apps?

@lucious 

Some of the most popular fitness apps, based on their user base and ratings, include:

1. MyFitnessPal: A comprehensive calorie counter and exercise tracker with a large food database.
2. Fitbit: Works with Fitbit wearable devices to track activity, sleep, heart rate, and nutrition.
3. Nike Training Club: Provides a variety of workout routines, personalized training plans, and guided videos.
4. Strava: Primarily used for tracking outdoor activities like running, cycling, and swimming, and provides detailed performance metrics.
5. Seven: A high-intensity interval training (HIIT) app that offers quick, seven-minute workout routines.
6. Fitbod: Generates customized workout plans based on personal goals, level of fitness, and equipment availability.
7. Sworkit: Offers a wide range of customizable workouts with video demonstrations and coaching instructions.
8. JEFIT: Focuses on weightlifting and strength training, providing workout tracking, exercise library, and training plans.
9. Couch to 5K: A beginner-friendly app that helps users gradually build up endurance to run a 5K race.
10. Runtastic: Tracks various physical activities like running, walking, and cycling, providing detailed stats and a GPS route tracker.

Note that popularity rankings may vary over time and across different regions.