Top iPhone fitness apps (screenshots)

4. FitnessBuilder

Cost: $9.99

Pros: FitnessBuilder comes with a massive library of targeted fitness routines as well as individual exercises; lets you narrow options by your location (gym, hotel room) and goal (core, flexibility); tracks completed workouts by date; includes a variety of calculators and stat trackers; offers a workout builder tool for easily tailoring your own routines.

Cons: It's expensive for an app, and it would be nice if there was a way to automatically play (properly timed) slideshows of routines to eliminate the need to swipe through each exercise by hand--an audio guide would be even better; it's not a simple app, and the complexity means it will take time and patience to use it to the fullest; the form used by some of the models is not perfect.

Good for: Experienced fitness freaks, dedicated exercisers who want a large variety of fitness routines with all the bells and whistles available in the palm of their hands, or anyone who wants to get in tip-top shape but can't afford a personal trainer.