Obsessive-compulsive disorder (OCD) is a psychiatric disorder affecting 2% to 3% of world population. Patients having this disorder engage in repetitive and discomforting behaviors usually linked to controlling or cleaning. The potential of technical solutions trying to support both patients and therapists has been to a limited extent explored with some encouraging results. However, the use of a mobile phone application has not yet been explored. We present a study of a distributed application, partly running on mobile phone and partly on a website, with four patients suffering from OCD and their therapist. Our qualitative evaluation yields encouraging conclusions for practitioners and developers of such applications.