Spending a few bucks on a smartphone application that tracks meals and exercise activity could be the easiest investment you make in your overall health. A recent study conducted at Northwestern University Feinberg School of Medicine in Chicago found that participants who used such apps (the type commonly available to smartphone users) lost an average of 15 pounds and kept it off for at least 12 months. The one caveat is that those successful with their diet and exercise programs also regularly attended health-education classes offered through the university during the yearlong study. (Classes were held twice a month for the first six months, once monthly thereafter.) The take-home here is that, yes, a cheap and easy phone app can help you achieve your fitness goals, but only if you’re committed to getting (and staying) in shape in other ways, too.