The following study tests the efficacy of an app-based program designed to improve child and family mental health and well-being. The intervention will include family-based activities for improving child and family mental health and functioning delivered as psychoeducation and activities through the smartphone app, as well as a just-in-time adaptive intervention (JITAI) component where AI analysis for family interactions will be used to provide real-time, dynamic feedback to families. Participants will be informed during consent that they will have a 50-50 chance of receiving the intervention. The study will assess caregiver and child functioning in a variety of domains, such as mental health symptoms, attachment style, and family conflict through a series of baseline and follow-up questionnaires. Caregivers may use their own smartphones, or they will be lent smartphones for the study. Caregivers and children will also be lent Fitbits/Apple Watches. The intervention will last 8 weeks. Data will include daily surveys, daily audio recordings, 15-minute surveys every 2 weeks about their experiences using the app, bi-weekly check-ins, psychoeducational modules, homework activities, JITAI sessions, and passively sensed data. The intervention will be administered through the smartphone app and will include daily 5-15-minute psychoeducation modules and practice sessions and daily JITAI sessions.