The role of cardiovascular magnetic resonance (CMR) in evaluating congenital heart disease continues to expand. This app aims to provide a day-to-day companion for those new to congenital CMR and for those looking for a quick reference guide in routine practice. The app gives an overview of the most common abnormalities and interventions as well as post-operative complications. It also provides typical scan protocols, key issues and a guide for reporting for each topic.