Health insurer Aetna (AET) says that more than 120 million adults in the U.S. own a smartphone and that 19% of smartphone owners have at least one health app on their phone. In anticipation of the continued growth of these numbers, Aetna has integrated the Care4TodayTM Mobile Health Manager mobile app, developed by Johnson & Johnson's (JNJ -1.23%) Janssen Healthcare Innovation, into its CarePass platform.

Fool analysts Max Macaluso and Rex Moore were at a recent mHealth Summit near Washington, D.C., and spoke with David Tripi of Janssen and Martha Wofford with Aetna's CarePass. In this video, Tripi and Wofford explain the Care4Today app.

Editor's Note: A previous version of this article incorrectly stated that Aetna and Johnson & Johnson co-developed the Care4Today app. The Fool regrets the error.