A lot of smartphone apps promise to help us lose weight. But do they really work? Experts say, “Yes” – some of them do!

A study in the Archives of Internal Medicine found that people who used programs that tracked their calories and physical activity lost 8 pounds more compared to people who attended weight-loss support meetings. But get this: The dieters who combined both methods – social support and a weight-loss widget – dropped TWICE as much!

The study’s lead author, Dr. Bonnie Spring, says the average dieter has a hard staying on top of the “nuts and bolts” of weight loss. So, an app that makes tracking calories and exercise easy helps them make better decisions especially when they come face to face with cookies in the break room, because they don’t want to have to add those cookies to their calorie count.

There are tons of apps available that help you track calories and exercise, monitor your weight, and provide forums where you can find support from other dieters. Here are a few Forbes magazine recommends – and they’re free: LoseIt.com, MyFitnessPal.com and Nike Training Club at NikeWomen.com.