The purpose of this pilot feasibility study is to evaluate the effects of a smartphone-based mindfulness intervention (MBI) on pain-related outcomes in individuals with fibromyalgia. This 8-week randomized controlled trial will compare an MBI app group to a control group who completes assessments only through the app. The MBI intervention includes weekly video content focused on mindfulness practice and psychoeducation, combined with daily symptom tracking through the app. Participants in both groups will complete self-report measures at baseline, post-intervention, and follow-ups at 3 and 6 months. The study will enroll up to 100 participants from Brigham and Women's Hospital and the greater Boston area. This pilot study is designed to assess feasibility and explore preliminary effects on outcomes such as pain interference, fibromyalgia symptoms, pain catastrophizing, sleep disturbance, emotional distress, mindfulness, and pain acceptance. Results will be used to inform the design of a future fully powered randomized trial.