“…Third, the theoretical basis of the intervention was confined to evidence-based components, consistent with the recommendations presented by Bakker et al [27] to create better and more rigorous mental health apps (MHapps). The chosen strategies were as follows: (1) focusing on nonclinical mental health, psychological well-being, and coping abilities, aiming to increase accessibility, enable preventive use, and reduce stigma, therefore avoiding the harmful effects of using mental illness labels [72]; (2) using self-monitoring and self-reflection—core features of many evidence-based psychological therapeutic techniques—to promote psychological growth and enable progress evaluations [73], with the advantage that MHapps make it possible for users to record self-monitoring data during their usual daily routines, while undergoing challenges or directly experiencing stressors [18]; (3) applying behavioral activation (ie, encourages individuals to engage in physiologically activating and psychologically rewarding activities) to boost self-efficacy, psychological well-being, and a repertoire of coping skills, since an app may promote self-discovery by encouraging an activity and then prompting reflection on the experience immediately after [74]; (4) presenting brief and passive psychoeducation to develop mental health literacy, in other words, to teach the participants about psychological processes underlying their distress and inform them about resources available to manage it [75]; (5) using real-time engagement to allow users to seek help for psychological challenges at the time they experience distress or soon after, thus opening new learning opportunities and applying coping strategies in ecologically valid contexts [76]; (6) promoting activities explicitly linked to specific mood problems to enhance understanding of cause-and-effect relationships between actions and emotions [77]; (7) using gamification—the use of “game-based mechanics, aesthetics and game thinking to engage people, motivate action, promote learning and solve problems” [78]—and intrinsic motivation to encourage app use via rewards and internal triggers, positive reinforcement, and behavioral conditioning, emergent approaches that may help counteract motivation problems and yield additional well-being outcomes; (8) providing reminders (email and push notifications) as external triggers for engagement, aiming to increase adherence and reduce dropout from self-help interventions [79]; and (9) conducting an experimental trial to establish the app’s efficacy before recommending it as an effective intervention.…”