You may sign up for HOOXI APP with your Naver, Facebook, Kakao Talk, or Google account. HOOXI provides customized greenhouse gas emission reduction and energy saving mission (hereinafter referred to as “Greenhouse Gas Emission Reduction Mission”) by analyzing the user profile such as lifestyle, age, gender, and occupation. Greenhouse Gas Emission Reduction Mission is designed to deliver various interesting knowledge about greenhouse gas emission reduction and energy saving to users. HOOXI users participate missions to reduce greenhouse gas emission, earn points by completing mission, and check ranking with other friends and groups. Every month, HOOXI users receive WGP as a reward based on the ranking and the ranking is initialized every month.