Can a health-care app make a difference between those who thrive and those who are barely alive? A Gallup/Healthways survey suggests apps have the power to do exactly that.

The two organizations have concocted the Gallup-Healthways Well-Being 5, which they describe as "a comprehensive, definitive source of well-being measurement." In their search to see what moves the dial on their well-being scale, they tested the use of mobile apps. First, they crunched the numbers on how many folks have downloaded a healthy living app:

• 65 percent of American adults have a smartphone;
• 34 percent have downloaded at least one healthy living app;
• 19 percent of all adults have downloaded and routinely use at least one such app;
• 23 percent of full-time workers have downloaded and use at least one such app.

The most commonly used healthy living apps, the survey revealed, were apps for calorie counting, healthy recipes and food/exercise diaries.

Gallup/Healthways then tested their well-being index. They looked at five areas defined as critical to an all-around healthy life: purpose, social, financial, community and physical. Definitions of the five areas are available.