Ethersocial has been created based on Ethereum. It focuses on optimized development of the reward system for online forums and games. Ddengle.com was created at 2013 and has become the biggest online blockchain forum in Korea. ESN project began with a discussion about reward system for contents based on text, image and video in the forum. We have focused on the development of various APIs which can utilize blockchain and practical applications through discussions with members of our forum about these issues. As a result of our effort, ESN has been launched in 2018.