The Johnson & Johnson Official 7 Minute Workout App (free, for iPhone) helps you squeeze some exercise into your day at an intensity level that's right for you. All you need is seven minutes, or about 11 if you add a warm-up and cool down, and a chair.

A medium-intensity Johnson & Johnson workout can include jumping jacks, pushups, wall chair, high-knee running in place, crunches, plank, side plank, tricep dips using a chair, and a few other moves. It's a lot to pack into seven minutes, but Johnson & Johnson gets it done.

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The app coaches you through each move as it comes up in the workout. A timer, in the form of a circle whose outline fills in bit by bit, functions as a visual aid for figuring out how much longer you have to keep up your stamina. There's no number on that clock, and I have mixed feelings about it. Part of me likes not worrying about the precise number of seconds, but part of me wants to know because I can't help but think that having more information would give me a better understanding of the workout.

One major complaint I have is that sometimes a left- or right-side exercise appears in your workout but a matching set for the opposite side is missing. I'm also fussy about doing an even number of reps (especially for exercises that work two sides of the body) and because the sets in this app are based on time rather than number of reps, it opens another opportunity to finish feeling lopsided. Another app that handles sets totally differently is Runtastic Six Pack Abs, which counts off each rep so you know how many you've done and the preferred pace for each move. I prefer that highly structured coaching to Johnson & Johnson's method of having you do as many reps as you can until time runs out.

Despite its name, the 7 Minute Workout App includes more workout options than just the seven-minute quickie. It has other premade routines, such as a Beginner 9 Minute Workout, The 21 Minute Cardio Blast, and a Core Workout. You can also create custom workouts by patching together any number of exercises the app contains, or you can complete a Smart Workout, which is built on the exercises that you've liked (i.e., tapped a "thumbs up" icon on) from previous workouts. In the custom workouts, you can adjust the number of sets and reps, as well as rest time between sets.

The Johnson & Johnson Official 7 Minute Workout App puts a heart-thumping routine at your fingertips for free. It isn't designed to help you reach a specific long-term goal, like some apps with "couch to 5K" plans do (try the app and heart rate monitor system PEAR Training-Intelligence or the simpler MyAsics app for that). And it's not a hardcore body building experience (try Touchfit GSP or some of the specialty in-app purchases in GAIN Fitness instead). But it does offer a solid workout that anyone can complete in a few minutes—ideal in a hotel room for sure.