PK Fitness is described as 'Effort-based workout tracker. Using the science of your body, the app tracks how hard you're working and tells you in real-time as your exercising, keeping you accountable and motivated every step of the way' and is an app in the social & communications category. There are more than 50 alternatives to PK Fitness for a variety of platforms, including Android, iPhone, Web-based, Apple Watch and Android Tablet apps. The best PK Fitness alternative is OpenTracks, which is both free and Open Source. Other great apps like PK Fitness are ASICS Runkeeper, Strava, FitoTrack and Google Fit.