RESUMEN
The General Data Protection Regulation (GDPR) regulates the processing of personal data in the European Union. The legal context is adapted to follow the evolution of technologies and of society. This new European regulation became mandatory, especially for connected devices, on May 25, 2018. An app originally known as "The Allergy Diary" is available for Android phones and iPhones. Its name was recently changed to MASK-air. The downloading and use of this app are free of charge and there are no adverts. It enables users to record their symptoms and their medications to better track the progress of their allergic rhinitis and/or asthma. It has been developed by public (Foundation FMC VIA-LR, University of Montpellier) and private (KYomed INNOV) organizations based in France and therefore falls under French jurisdiction. This article summarizes the five main principles of personal data protection to be respected during the development of the app: purpose, proportionality and relevance, limited retention period, security and confidentiality, as well as the rights of the people who are involved in the management of the personal data (including withdrawal and modification).