RecruitingBehavioural interventionDevelopment and Testing of a Mobile App to Scale Delivery of Cognitive-behavioral Therapy for Avoidant/Restrictive Food Intake DisorderAvoidant/restrictive food intake disorder (ARFID) is a serious and impairing eating disorder - occurring in up to 4% of adults - for which most individuals do not have access to treatment. The proposed study aims to develop and test a mobile app to scale delivery of cognitive-behavioral therapy for ARFID. Knowledge gained will contribute to the development of a clinically accessible, scalable, inexpensive treatment for ARFID, a highly impairing disorder for which there are significant barriers to care access.