COMJUNTOS is an app that helps families with a child with a rare disease navigate the main communication situations with healthcare professionals. The common thread is seven challenges that invite families to overcome some of these situations, such as the day they receive a diagnosis, a doctor's appointment, a medical report, or a medical test. Each challenge includes a video with real testimonials from affected families and healthcare professionals, a hypertext that explains the situation and anticipates any questions that may arise, a basic dictionary of medical terms, and information on tips, resources, and links.