Defense health officials are testing a tool to give service members a mental health boost on demand. It’s a mobile app called the Virtual Hope Box. Each user can customize it. Mark Reger is the deputy director and chief of research at the National Center for Telehealth and Technology, which is part of the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury. He explained the app’s purpose when he joined Tom Temin and Emily Kopp on the Federal Drive.