The purpose of the iEDEN application is to enable participation in the new survey at 16-19 years of age for children in the EDEN cohort. This new follow-up, called iEDEN, will seek to understand better the influence of screen use on the health and development of adolescents included in the cohort. The project will rely on data collected in previous EDEN cohort follow-ups and new data collected through this application. For 7 days, the application will make it possible to estimate the time spent using the smartphone, the type of activities and applications used on a daily basis (for example, games, streaming, messaging) as well as movements thanks to geolocation. After these 7 days, questionnaires (10 min) will be sent to the application to learn more about the participants' lifestyle, development, and health.