Remember when phones were for calling people? Today, chances are good that someone close to you is not just using their phone to text friends, surf social media or check their email, they're also using it to help them lose weight or manage a health condition. But are these increasingly popular health-related smartphone apps actually effective? Questionable value The IMS Institute for Healthcare Informatics recently released results of the largest scientific study of its kind into healthcare apps. The research team deemed around 16,200 apps in the Apple app store to be legitimate healthcare apps for consumers. They tested and ranked those apps in a wide range of categories, such as functionality and quantity and quality of information. The results were not exactly impressive. On a 100 point scale, more than 90% of the apps received 40 points or less. But a few rose to the top. Here are just a few examples of health-related apps that the IMS Institute deemed more useful than the rest. Weight loss One of the most downloaded health apps in the Apple app store, the Calorie Counter and Diet Tracker by MyFitnessPal HD, received high marks in the IMS Institute study. In this app, you are asked to enter the foods you eat into a diary, and the app does the math for you, along with setting exercise and weight goals and linking you to friends. The Calorie Counter PRO app by MyNetDiary Inc. also received a good rating. But although the study found the information in these apps to be useful, it's important to note there is no solid evidence that these apps are effective in helping you lose weight. Diabetes The IMS Institute study liked the Daily Carb app by Maxwell Software. It helps you track your daily intake of food and water, along with blood sugar levels and insulin doses. Also ranking highly in this category were Glucose Buddy by Azumio Inc., and GoMeals by Sanofi-Aventis U.S. LLC. Another diabetes app worth noting, Tipping Points by WellDoc Diabetes Management, is one of only about 100 health apps that are approved by the FDA. This app is also rare in that it's been tested in a clinical trial, which found it was effective in improving patients' blood sugar management. Cancer Could your phone help you catch cancer at its earliest stages? Apps like Dr. K's Breast Checker offer interactive tools and reminders to help women keep track of changes in their breasts. Another cancer-related app ranking high in the study was SkinKeeper. This app helps users monitor moles, assess their risk factors through personal and family skin history and share their data with their doctor. Fertility Whether you're hoping to expand your family, or to ensure that you DON'T add three more years of diapers to your life experience, apps like the Ovulation Calendar can help you predict your fertile days by tracking your menstrual cycle, body weight and temperature. If you have a baby on board, your phone can also help you learn about and celebrate each stage of pregnancy with apps like Pregnancy Tracker from WhatToExpect.com, which the study ranked highly. Diagnosis Answers to your medical questions can be found at your fingertips through HealthTap, an app that provides free, vetted health information from doctors for any symptom, condition, medication or health concern. Also ranking highly in the study was WebMD for iPad, which offers a symptom checking program, plus information on drugs and treatments, first aid and local health listings. Healthy skepticism Any health app is only as good as the data you provide it, and, keep in mind, it will likely be less personalized and less private than a health care professional. What has your experience been? Has a health app helped you change your life, steered you off-course, or wound up in your trash bin? Share your experience with us at firstname.lastname@example.org.