I love this idea! Expanding off of your nutrition idea, I agree an educational aspect would help increase the adoption of healthier eating habits. Tracking steps, exercise, sleep, etc. are great metrics to encourage a more active lifestyle, however a large part of one's health is determined in the kitchen. There are numerous health blogs with recipes and incorporating a diet plan based on fitness/health goals can help users get all aspects of their health on track. Based on the time of year, presenting recipes based on fruits/vegetables that are in season will teach people how to eat fresh and hopefully local. I cannot wait to see how this project progresses!