Want a smarter workout tool? Try your smartphone! A slew of free, effective apps is available on Android and iOS mobile devices—you just need to know where to look.

One of the most popular apps is Nike Training Club, free on iOS and Android. You’ll get a summary of your own training performance on the home page, and details of previous workouts that you can access via a menu bar. Plus, you can choose your workout, depending on your goals. (And there’s a rewards center with cool digital badges for when you complete your workouts.)

If your device runs on iOS, a terrific option is Gain Fitness Cross Trainer. The popular Full Bod Livelong and Torso Rush workouts come with the app, and they’re easy customize. The app also suggests when, where and how you should exercise, based on your goals. Feeling social? Share your performance on Twitter and Facebook. Feeling lonely? The app even gives voice encouragement like “nice!”

For Android users, a similar free app is Workout Trainer. This also has voice cues, along with simple animated instructions for each exercise. One caveat: In the free version, the trainer “voice” is electronic (which can be irritating). But if you enjoy having a virtual cheerleader, the $15-a-year subscription-based version includes more realistic rah-rahs.