A mobile health (mHealth) app that addresses both early intervention and prevention of problematic childhood anxiety is presented in this paper. The app is based on the childhood anxiety protocol REACH. Appropriately, user-centered design (UCD) reflects the needs and preferences of the young target audience.

The introductory section outlines the setting and issues motivating this project. The second section explains the elements of the REACH protocol. The protocol has been somewhat effective in non-automated implementation, but automation promises increased effectiveness. The next relatively lengthy section lays out the design process. After gap analysis by subject-matter experts (SMEs) that focused on the REACH components and the issues in porting them to a mobile environment, a patient-centric process for design was adopted to better address the issues that emerged. The design team used personas, rapid prototyping, participatory design by SMEs, and ultimately validation by the end user. The fourth section addresses app implementation on the Android platform and includes explanation of the various activities ported from REACH. The next section concerns validation by an advisory board and also from a usability study. Statistical analysis of the usability study is included. The paper closes with a discussion that compares other research in the literature with this approach and that also looks at future plans for follow-up work based on lessons learned. Sixteen relevant references as well as helpful figures and tables are provided.

The multi-disciplinary authors have delivered a significant paper that is well organized and well written. The paper should appeal to a range of researchers in mobile apps and in psychological intervention.