If you want to follow a workout plan that takes your Rep Max information into account, locate the workout plan in the "Plans" tab and follow the workout plan as you usually would in the Exercise.com app.

Then, when you are customizing the plan's details, look for the Rep Max entry field below the workout days options. Enter your Rep Max information and the correct weights will be automatically programmed into the workout plan.

When you are finished, tap the done icon in the upper corner of the screen, and your Rep Max information will be added to the workout plan. 

When you go to log your workouts, the exercises from the plan that include progression percentages will display the weight that you should use!