Managing attention, progressing towards goals, and monitoring behaviors are elements of self-regulation (SR). SR applications based on contemplative practices such as breath counting have demonstrated gains in field studies but have failed to engage youth without coercion. Prior research generated behavioral and neurological changes, but was disliked by youth. This three-part study includes a participatory design workshop, application redesign, and subsequent field deployment to understand how wearable devices can support self-regulation. Twenty-seven youth designed activities that revealed interest in and models of self-regulation that became part of a smartwatch app. Researchers revisited and redesign the application based on youth feedback, and then released the redesigned application (some of whom participated in workshops, some of whom did not). Redesigning the application to be responsive to youth needs resulted in higher levels of satisfaction than previously observed. Youth also used this application more often and reported higher use. Three design tensions persisted: (1) Breath counting applications as attention grabbing vs. attention cultivating and (2) breath counting activities as a relaxation activity vs. a mental workout, and (3) exposing youth to meditation and breath counting as a strategy for developing healthy minds vs. an institutionalized or compulsory required action. Activity occupied positions along these continua, which creates associated challenges for researchers. A fruitful design space exists for researchers to integrate attention focusing into activities that youth value, which can include stress reduction or mindfulness training, but also could be simply to improve their academic work.