531 Trainer is a free iPhone app developed by Kevin French, designed to streamline yourtraining experience. Say goodbye to cumbersome spreadsheets and workout jitters at the gym. With this app, you can input your max for military press, deadlift, bench press, and squat just once, and have each day's workout conveniently calculated for you. Transitioning between cycles is a breeze - a single tap increments the weights for your lifts, allowing you to seamlessly progress in your training.

The app features a One Rep Max Calculator, Assistance Work Percent Calculator, supports both Kilograms and Pounds, ensures program persistence, and provides visual guidance on the weight plates to use for each workout.