2.2.4. Smartphone App
’ behavior
DELAYED DELIVERY
The aim of the HHS smartphone app was to promote well-being and support students’ behavior changes outside school hours by influencing their knowledge and awareness of stress, sleep, PA, and meal habits. The app included articles, tracking options, recipes, training programs, quizzes, time management techniques, mindfulness practices, and an option to sign up for four different eight-week courses on how to prevent stress, increase PA, and improve sleep or meal habits. The app was developed in collaboration with a company which specialized in designing personalized digital health programs. The research group developed and wrote the main part of the content, while the app company designed the layout and technical functions of the app. The content about stress was based on academic books, scientific literature, and recommendations from the Danish Health Authority. The focus was on writing short texts in a non-academic language, inspired by youth magazines to appeal to young people. Contrary to the original implementation plan, the app was introduced to the students 12 weeks after the introduction of the intervention due to a delayed delivery from the app developing company. Students were introduced to the app by teachers at the school or by a member of the research group. Students received written information about the features of the app and were shown a tutorial video to illustrate how the app worked. We used gamification to motivate participation and posted three competitions on the app from November 2016 to April 2017 to encourage more students to download and use the app.