Fitbit and other apps allow users to track weight loss over time but some wish they provided more metrics like strength, endurance and flexibility to see overall improvement. The document discusses a fitness app that aims to connect users with personal trainers, track various workout metrics and plan customized routines to help users meet their goals in the large personal training and gym markets. It provides examples of how a user named Claire could see her past workout details, goals and get anonymous feedback from trainers within the app.