Trial Flow Diagram. This figure presents the trial flow diagram of identifying eligible articles for this study. A total of 2,894 articles were returned from the literature searches. Initially, a total of 2,780 articles were screened based on their titles and abstracts satisfying the inclusion and exclusion criteria. An additional 59 articles were excluded after full text review of 114 articles. Finally, 55 articles discussing 83 smartphone-based healthcare applications met the eligibility criteria. The earliest eligible articles were published in 2003, and 24 of the 55 articles were published in 2010 through April 2011.