Abstract
This study developed and evaluated a theory-driven mobile app to facilitate pro-environmental behavior change and habit formation to address the prevalent attitude-behavior gap in environmental activism. The app first informs users of interconnected environmental problems and offers various pro-environmental behaviors for users to practice daily. The app further nudges users toward achieving their behavioral goals through personalized daily reminders, progress-tracking, empowering messages that celebrate their achievements, and reaffirmation of the beneficial impacts of their actions to facilitate eco-habit formation. To evaluate the app's effectiveness, a sequential mixed-design method combining a pre-and-post-design experiment and focus groups was conducted. Quantitative and qualitative assessments indicated the effectiveness of this mobile app in fostering the development of eco-habits.