USS is a decentralized application platform. It provides a set of SDKs and APIs to help developers build decentralized applications based on Javascript and sidechain technologies. USS is committed to creating an easy-to-use, full-featured, plug-and-play system by providing integrated industry solutions such as custom sidechains, smart contracts, and application hosting. With the USS ecosystem, developers can quickly iterate their Javascript applications and publish them to the system's built-in app store, which can be downloaded and executed by distributed nodes in the platform and serve the average user. The whole process is honest. A secure USS sidechain consensus network provides security assurance.