Traumatic injury is the leading cause of mortality in the U.S. for young people, and a source of long-term morbidity in all ages. A majority of trauma patients report chronic pain (CP) and disability at 4-months (30%- 79%) and 12-months (63%) post-injury. Maladaptive psychological processes have a stronger association with the transition to CP than does injury severity. Posttraumatic stress disorder (PTSD) symptoms (e.g., intrusions, avoidance and hyperarousal) occur in up to 22% of post-injury patients and herald the transition from acute to CP. Although psychological interventions can modify PTSD symptoms, and reduce CP, it is unknown if early intervention to prevent PTSD symptoms can prevent post-injury CP altogether. "PTSD Coach" is a publicly available, free, mobile app that provides scalable and psychosocial support modeled on principles of cognitive-behavioral therapy. PTSD Coach has helped Veterans and civilians to manage PTSD.