thx! is a decentralized application that can exchange “thank you” token with a mobile device. The received thx! token (THX) will be easily transferred from one person to the other. The usage examples can range from service-oriented settings such as restaurants, parking lots, hotels, to formal settings such as workplaces, conferences. Transaction history of thx! is not only recorded on the timelines of both giver and recipient, but also on the blockchain network.