With about 9,000 consumer health apps currently available in the iTunes store, it seems like almost all smart phone users can download their way to better health these days.

The store offers a mindboggling array of creative apps, including ones that calculate calories burned during exercise, create soundtracks to help people fall asleep, and display pictures that can elicit memories from Alzheimer’s patients. If the store doesn’t offer something for what ails you now, it probably will soon. The selections will proliferate within the next year, with an additional 4,000 consumer apps expected by next summer, industry experts say.

But all this innovation creates a bewildering set of problems. It’s hard to figure out what apps are available, let alone which work best. Health apps may have the potential to dramatically improve people’s lives, but those based on misleading or bogus information can cause serious harm.

“Apple isn’t testing apps for their scientific validity,” said Dan Cohen, a social worker who has reviewed apps for their effectiveness.

Given the stakes, it’s no surprise that the government is starting to regulate these smart phone applications. Just last month, the Federal Trade Commission brought its first cases against the makers of two health apps. Each claimed to cure acne with colored lights emitted from cell phones.

“Smart phones make our lives easier in countless ways, but unfortunately when it comes to curing acne, there’s no app for that,” the FTC chairman said, when announcing the crackdown. The agency cited the makers of AcneApp, which had sold about 11,600 downloads of its $1.99 app, and the developers of AcnePwner, which sold 3,300 downloads of its 99 cent app.

The Food and Drug Administration (FDA), meanwhile, proposed regulations this summer for apps that could be considered medical devices. The agency, which is seeking comments on its proposals until Oct. 19, may focus on apps that are accessories to established medical devices used by doctors, such as smart phone apps that can display X-rays.

It could also regulate apps that transform smart phones into medical devices by using sensors or other attachments. Already, the FDA has approved gadgets that turn smart phones into blood pressure-monitoring cuffs and pocket ultrasound machines.

Apps that connect to consumer devices, such as blood glucose meters, may be regulated, too, if the apps display or analyze the meters’ readings, the FDA says.

The majority of health apps will almost certainly not be considered medical devices and will escape government scrutiny. But some app developers are voluntarily going through the laborious FDA clearance process, in part, to convince the medical community that their products have real clinical value.

WellDoc, a Baltimore-based health care company, got FDA approval last year for its DiabetesManager, which provides automated diabetes coaching for patients. The app also was tested in a randomized clinical trial conducted by the University of Maryland’s medical school, which found that patients had a statistically significant improvement in their blood glucose levels after using the app for a one-year period.

Scientists have found flaws with other apps.

When a George Washington University professor conducted the first content analysis of behavior-modification apps, she discovered that few of the 47 smoking-cessation apps available in 2009 followed evidence-based health guidelines. Lorien Abroms, a public health professor, concluded that the apps had “serious weaknesses” because they did not link to quit lines or clinics or suggest ways for smokers to get social support from family and friends.

She argues that public health apps should be developed from evidence-based guidelines and should offer users the chance to receive text messages. Studies show that text messaging can help people change unhealthy behaviors.

Many public health organizations have developed useful apps. The American Heart Association has one to help people find walking paths, while the New York City Department of Health, in its effort to help reduce the spread of sexually transmitted diseases, lists places that give away free condoms.

Such health apps are already popular and may soon be ubiquitous – with 500 million consumers projected to be using them by 2015. Nine percent of smart phone owners surveyed last year said they use health apps, Pew Research Center study found. Younger people downloaded them most frequently, with 15 percent of smart phone owners between the ages of 18 and 29 using them. Black owners also had higher user rates, with 15 percent of those surveyed taking advantage of them, compared to 11 percent of Hispanics and 7 percent of whites.

The most popular types of consumer health apps focus on fitness and diet, according to a report released last month by MobiHealthNews, which tracks mobile health issues. About 16 percent of available apps in the iTunes store focus on cardio fitness, with some running apps claiming millions of users, MobiHealthNews says. Another 14 percent of apps are aimed at improving people’s diets, while another 11 percent deal with stress and relaxation.

“Consumers trying to keep up with the ever-changing app market may want to consult medical societies, like the American Cancer Society,” says Cohen, who evaluates apps. Alternatively, they could download Cohen’s own app, Healthful Apps, which highlights some of the most effective, user-friendly health apps available.

Cohen said he spent more than a year perusing and testing apps before coming up with his list. He focuses on apps in eight categories, including relaxation, caregiving, memory improvement, and communication.

Among his favorites: iTriage, an app designed by two emergency room physicians that helps patients understand their symptoms and provides information about the closest clinics and hospitals – including wait times at some emergency rooms.

Cohen says that he sometimes uses the Asleep app when he has insomnia, and also likes sleep apps that send different sound tones to each ear, called binaural tones. He is a fan of Panic Control, an app designed by a California psychiatrist that helps people during panic attacks, as well as apps that test people’s hearing and vision. He likes such testing apps, not because they can replace doctors, but because they can serve an important public health function of encouraging people to seek professional help when they need it.

For caregivers of the elderly, Cohen likes Elder 411, an app designed by a geriatric care manager filled with more than 500 pieces of advice, and Alzheimer’s Cards, an app filled with pictures that can spark memories, based on the book, “Simple Pleasures for Special Seniors.”

For an app that has completely transformed the lifestyle of people with disabilities, he picks Proloquo2Go, a text to speech app that allows people with autism, cerebral palsy, and various brain injuries to communicate more easily.

Cohen also endorses Pain Care, which recently won the “Project HealthDesign” challenge sponsored by the Robert Wood Johnson Foundation and California HealthCare Foundation. The app lets patients track pain symptoms and share data with their doctors. It is designed to help people figure out what exacerbates their pain and what treatments are most effective.

It’s impossible to know how the next generation of consumer apps could change patients’ lives. But almost everyone agrees with one statement made by FDA deputy director William Maisel, when he spoke at the agency’s recent hearings on apps and said.

“These types of products will revolutionize the way we deliver health care.”

Contributing Writer Rochelle Sharpe is a Pulizter Prize-winning journalist with more than 25 years of health writing experience. Sharpe’s bi-monthly news feature for the Health Policy Forum focuses on issues related to health, wellness, and prevention. As a leading nonprofit health care research and consulting institute dedicated to improving human health, Altarum encourages open discussion and debate about the many challenges in health care today. All postings to the Health Policy Forum (whether from employees or those outside the Institute) represent the views of the individual authors and/or organizations and do not necessarily represent the position, interests, strategy, or opinions of Altarum Institute. Altarum is a nonprofit, nonpartisan organization. No posting should be considered an endorsement by Altarum of individual candidates, political parties, opinions, or policy positions.