The advances in and widespread adoption of mobile technology after the turn of the 21st century led to an explosive growth in software applications (apps) designed to perform particular functions on smartphones and other portable devices. The emergence of apps that share psychological knowledge or help implement psychological interventions represents a seminal step in the history of efforts to integrate technology into the practice of psychology. Such mental or behavioral health apps are also integral to both the quantified self movement (tracking aspects of one’s daily life to improve functioning) and the broader field of mHealth (using mobile technology to support health care).

The proliferation of psychology apps, their increasing integration into both clinical practice and the daily lives of individuals, and their potential to profoundly ...