Beachbody, LLC has P90X Tracker (iTunes Link) for the iPhone and iPod Touch in the iTunes App Store for FREE (regularly $4.99) for a limited time.

P90X has evolved. The breakthrough workout program that revolutionized home fitness now has an app that lets you Bring It! on your iPhone, so you can get even more amazing results—and work out with P90X anywhere. Keep track of your sets, reps, and weights, view your progress, log your nutrition, and share your results. With interactive features like these, you’ll stay motivated and accountable to get more out of P90X than ever.