USS is a decentralized application platform. It offers a suite of SDKs and APIs to assist developers in building decentralized applications based on Javascript and sidechain technology. USS is dedicated to creating an easy-to-use, fully-featured, plug-and-play system by providing integrated industry solutions such as custom sidechains, smart contracts, and app hosting. With the USS ecosystem, developers can rapidly iterate their Javascript applications and publish them to the built-in app store within the system. These apps can then be downloaded and executed by distributed nodes within the platform, serving everyday users. The entire process is securely guaranteed by the honest and secure USS sidechain consensus network.