Superuser is a free and must have android app that grants system access to rooted Android devices. You can download superuser from above links. You can get superuser download mirror for Android or Super User Stable update .This SU app is also used to manage which android apps have root permission as well as monitor their usage of the permission This is latest Super User app for almost all phones and all android versions.We are frequently updating the latest Super User download links.
Source: http://superuserdownload.com/