PHAT - Workout Tracker is a free iPhone app developed by App Factory LLC. It falls under the Lifestyle category, specifically Health & Fitness. This app is designed to help users increase muscle size and strength through a combination of powerlifting and bodybuilding techniques.

The PHAT weight lifting workout program focuses on both upper and lower body, with a blend of power workouts and hypertrophy workouts. Hypertrophy days aim to increase muscle size, while power days focus on building strength to lift heavier weights on hypertrophy days.

One of the key features of this app is its ability to guide users through each exercise, set, and rep, ensuring proper form and technique. It also allows users to customize their workouts for a personalized approach to strength and muscle building.

In addition, PHAT - Workout Tracker provides various tools to enhance the user experience. It offers graphs and analytics to visualize progress and gains, a built-in plate calculator to help calculate weights, and a rest timer to optimize rest periods between sets. The app supports both US and metric units for convenience.

With its comprehensive features and user-friendly interface, PHAT - Workout Tracker is a valuable tool for individuals looking to enhance their muscle size and strength effectively.