Habitree : A mobile application developed to nudge youths to make eco-friendly choices

This report describes the development of the mobile application Habitree, designed to nudge individuals between the ages of 15 to 25 towards more sustainable daily habits. The development of Habitree is based on behavioural science theories of nudging, gamification, and motivation to enhance user self-efficacy and leverage social norms. The purpose of this project was to explore how IT-based solutions could motivate sustainable behaviour through daily self-reporting and gamification to improve engagement. The methodology included a preliminary survey of 58 youths to map their interests in and knowledge of environmental habits. This was followed by an agile application development process in React Native in Expo with a local data storage to ensure GDPR and privacy compliance. The app offers daily habit tracking of four themes: transport, diet, shopping and general habits. The value of the points given for the habits align with the UN Sustainable Development Goals, and visual feedback is presented via an animated growing tree, color-coded calendar leaves and a weekly performance chart. Usability tests (n=15) and focus group (n=7) showed high usability and that visual elements, particularly the tree, strongly motivate continued use. Some refinements were suggested and taken into the final product, such as some visual clarification. With these results, the application successfully functions as intended and motivates the target group to continue using the application and to improve their daily habits.