Fast and Fit is a free lifestyle application available on iPhone designed by Renju Thomas. The app aims to assist users in analyzing their race performance and maintaining a healthy running routine by ensuring they have adequate running shoes. Key features include the Running Time Converter, which predicts race times from 600m up to 10k, and a Machine Learning Tool that assesses the quality of running shoes through pictures. Users can also access information on various running form issues and injuries, although it is recommended to consult a doctor before making any medical decisions.

Fast And Fit offers valuable tools such as the Running Calculator Formula by Pete Riegel to enhance the running experience, making it a comprehensive companion for individuals looking to improve their running performance and prevent injuries.