Want to find a step aerobics class you can hit on your way home from the office? For the members of many fitness clubs today, there’s an app for that.

Smartphones now make up almost 30 percent of all wireless phones in the United States, according to a Nielsen report, and researchers Gartner Inc. predict that the web-enabled phones will replace computers as most people’s primary means of accessing the Internet by 2013. In response, forward-thinking companies are increasingly investing in making their brands accessible to smartphone users through mobile-friendly websites and mobile applications. And that includes many major fitness club industry players—24 Hour Fitness, LA Fitness, Crunch and Gold’s Gym, to name a few.

Most club apps offer at a minimum the basics that a member or prospective member would look for on the club’s website, such as location information, class schedules and facility photos. But beyond that, the features and accessibility vary greatly, depending on each club’s strategy in creating its app.

For Crunch Fitness, New York, an app was a must-have, says Christina DeGuardi, the company’s vice president of marketing.

“Our member base is pretty young and savvy,” DeGuardi says. “Their usage of our website is so high that we knew that an app was something that our members would appreciate and that could become part of their daily routine.”

Crunch worked with IdeaWork Studios, the digital agency responsible for the crunch.com website, to create the mobile app, which launched in mid-January after around two months of development. The app is linked directly to the website, which means that when Crunch staff change a group exercise class time or a club’s contact details on crunch.com using the company’s content management system (CMS), it automatically is updated in the app, too.

Although anyone can download the free app, the user must enter a Crunch membership number to access its features. At press time, figures included 6,000 iPhone downloads and 4,000 Android phone downloads, meaning that more than 10 percent of all members downloaded the app within its first five weeks, DeGuardi says.

The app’s most used features are a check-in function, which allows users to pull up a mobile membership card for reception staff to scan, and a class finder that lets members search by class name, instructor, time or location.

The app also has a version of the website’s members-only iCrunch section, which users can personalize by setting their favorite classes, tracking their goals, and maintaining a photo log.

The app cannot be utilized by nonmembers, but DeGuardi says that it is still a useful recruitment tool for Crunch.

Members can choose the “shout your check-in” setting, which automatically updates their Foursquare, Facebook and Twitter accounts with their whereabouts when they arrive at a club. They also can use the app to send a two-week guest pass to a friend or post a referral as a link on their Facebook walls to offer a guest pass to all of their friends.

DeGuardi would not specify how much Crunch spent to develop the app, but says the range of pitches went from $40,000 up to $100,000.

“I can say that a lot of companies were coming back and saying that for the things we wanted to do, the development would be about $100,000—and we didn’t even get close to that,” she says.

Whatever the initial investment, DeGuardi says the app is producing returns via the referral feature and a specials section where the club offers discounts on merchandise and services.

Crunch already is working on phase two of the app, and DeGuardi hints that the next version may offer features for nonmembers.

“That’s definitely on the radar for something we might want to do going forward,” she says.

Gold’s Gym International, Irving, TX, took a different tack when it launched its Spotter app last August, making almost all features relevant to nonmembers.

Spotter offers club and class locators for its members, but the majority of its features will appeal to anyone who wants to get or stay in shape. There is a goal countdown function, a calorie equator that calculates the time one would have to do a certain such activity to burn off a meal or snack choice, and a photo album that allows the user to load photos of themselves then see their fitness progress in a flipbook format. David Reiseman, vice president of communications at Gold’s, says the company’s aim was to go beyond the features they saw on other club apps and offer something more dynamic than club information.

“Our thinking was, if you’re a member, this will be a great resource for you, and if you’re not a member, it will help establish a new connection with our brand,” Reiseman says. “Hopefully, that turns into them becoming a member, but even if it doesn’t, if we’re creating more fans or helping more people get results, then that to us is a success.”

So far, the plan is working. Reiseman says that the more than 70,000 people who have downloaded the app since its launch about six months ago are “a healthy mix” of members and nonmembers.

That number should rise significantly when the app is rolled out for Android-based phones. (Phones running Google’s platform are now outselling Apple’s iPhone, according to Nielsen.)

The app was developed by New York-based mobile marketing firm Joule, and its mission to get nonmembers acquainted with the Gold’s brand is part of the company’s overarching Know Your Own Strength campaign, which Gold’s launched in late 2008 with the help of its lead advertising agency, McKinney, Durham, NC.

Part of the Know Your Own Strength campaign is to get people to see and interact with Gold’s in a new way,” Reiseman says. “We’ve perhaps had a reputation in the past for being intimidating or hardcore—and while we’re proud of our heritage, this new platform is more reflective of who we are as a brand today.”

Today’s Gold’s is no longer the “mecca of bodybuilding” made famous by Arnold Schwarzenegger in the 1970s but, as Reiseman points out, a full fitness experience with cardio cinemas and group exercise classes. However, he says that some things haven’t changed.

“The Gold’s Gym brand has always been a little irreverent and always had a little bit of an attitude, but in a fun way,” Reiseman says. “And that’s what we tried to express with the app through features like the motivation shaker.”

That feature is one of the many that is relevant to nonmembers. When a user selects the app’s motivator feature and shakes the phone, a motivational and usually funny statement pops up.

Shake it once and you get tough love: “You’re worth it. Now act like it.” Shake it again and it’s a witty pep talk: “I might be just a dumb old cell phone, but I believe in you.” And they’re not just aimed at getting users into their nearest Gold’s: “Call a friend. Invite them on a walk. If they can’t make it, walk anyway.”

The Spotter app has a link to a page on the Gold’s website where users can request a 7-day guest pass, but otherwise it doesn’t drive revenue in any direct way—users do not pay for the download, and it features neither third-party advertisements nor special promotions for members.

However, Reiseman is resolute that the app does contribute to the bottom line.

“It does it through retention, brand awareness, buzz,” he says. “I can’t share the benchmarks that we set internally, but I will say that it’s exceeding all of our expectations.”