The purpose of the chapter is the analysis of mobile applications as performance and informal learning support tools that facilitate the development of the psychotherapy process. The “e-therapy” has become a common term to refer the delivery of mental health services, on-line or related to a computer mediated communication between a psychotherapist and the patient. Initially, a background on e-therapy will be provided through the analysis of the existing related literature, the description of the state of the art. After this general view as starting point, the “self-help therapy”–a kind of e-therapy where the concept of patient empowerment is important– will be exposed to depict the importance of patient activities beyond the clinical settings in the rehabilitation process. Then, the integration of mobile devices in the psychotherapy process will be explained considering how their technological features support patient therapeutic activities like behavior assessment and informal mobile learning. The relation of the mobile devices with psychotherapist work activities such as evidence gathering and patient monitoring will also be explained. The chapter follows with a discussion on the mobile learning practices as a source of potential strategies that can be applied in the therapeutic field and finally a set of recommendations and future directions are described to explore new lines of research.