Purpose There has been a substantial increase in the use of smartphone applications (apps) to monitor, evaluate and manage mental health symptoms (Research Guidance, 2017). While many treatments could benefit from the incorporation of mental health apps, exposure therapy could particularly benefit from real-time data collection to help counteract patients’ retrospective recall biases. This small-scale study (n = 16) assessed a university developed mental health app called ETMOS by evaluating its perceived usefulness in planning, implementing and evaluating exposure therapy. Methods Six psychotherapists and 10 patients were recruited from two outpatient clinics at the Center for Psychological Psychotherapists (CPP) in Mannheim. After using ETMOS for one week, participants evaluated its engagement, functionality, aesthetics and information quality, as well as its subjective quality by filling out the German end-user version of the Mobile App Rating Scale (uMARS-G). All items were rated on a 5-point scale (1 = inadequate to 5 = excellent). Results Participants rated ETMOS with an above average rating on the aesthetics, functionality and information subscales (3.76, 4.04 and 4.09, respectively) and with an average rating on the engagement subscale (3.27). Overall, ETMOS had an above average total score (3.78, SD = 0.29) and received 3.6 out of 5 stars on the subjective quality subscale. Additional analyses showed that uMARS scores were not related to frequency of use or participants’ age. Conclusions This study gained valuable information regarding the user friendliness and clinical applicability of ETMOS. Future research should assess its influence on long-term therapeutic outcomes.
