Roundabuy is a mobile application that aims to provide an all-in-one but simple-to-use tool for sellers and buyers using social platforms. With Roundabuy,buyers can place orders and send enquiries to sellers. Both sellers and buyers can keep track of orders』 progress and can communicate conveniently through the app. Besides the user-friendly interface, Roundabuy also provides various e-payment solutions, making the purchasing experience smoother. Through the unique post-sales service platform, sellers are able to reach buyers and develop customer loyalty. This app simply saves sellers develpment time and costs.