This mobile and web app enables users to estimate carbon emissions and receive tips for reduction. Leveraging React Native for cross-platform development and native performance, the app uses UK’s conversion factor data to accurately estimate carbon emissions. I integrated a serverless backend using AWS Lambda to serve both mobile and web applications, ensuring scalability and reducing operational costs. Users can complete a short questionnaire to estimate their annual carbon emissions, update it to reflect new habits, and log daily activities to track their carbon impact and resource usage. The app encourages eco-friendly choices by providing tips on sustainable practices and allows users to join or start campaigns to discuss and share tips with others on how to protect the environment.