OptiMAT (or “Optimizing Medication-Assisted Treatment”) is a health and wellness app under evaluation at the University of Arkansas for Medical Sciences (UAMS). Medication-assisted treatment, or MAT, is the use of medications combined with therapy to treat substance use disorders, including misuse of nicotine, alcohol, or opioids. UAMS is evaluating if OptiMAT can improve treatment outcomes through (1) daily monitoring of participant craving, mood, and withdrawal symptoms, (2) personalized feedback, and (3) alerting participants when they enter areas of high risk for relapse.