Inclusion Criteria:  (1) aged 18 years old or older, (2) currently registered as an undergraduate or graduate student, (3) has previous active military service from any U.S. military service branch, (4) has at least daily access to their own Apple iPhone (version 5 or later) or Android phone, and (5) have posttraumatic stress disorder (PTSD) symptoms (must have a score of 33 or above on the PTSD Checklist for DSM-5)  Exclusion Criteria:  (1) Those who have a score of 32 or below on the PTSD Checklist for DSM-5 and (2) Those who have a cognitive impairment such as dementia-related disorders.