There has been a substantial increase in the number of health-related smartphone applications (apps) available to consumers in recent years. How does one decide which apps have scientific evidence backing their claims and which are "fake news"? In this Commentary, we explore the hierarchy of scientific claims and review recent literature to identify areas of Health Education and health promotion in which evidence-based smartphone apps are available. Further, we present a theory-based framework to help app developers optimize their potential to enhance human health.