OpenVPN for Android is a open-source VPN client based on the open-source OpenVPN project. It uses the VPNService API and doesn't require a rooted Android.
It's important to keep in mind that OpenVPN for Android is a client to connect to a VPN server. In other words, there has to be a server 'on the other end of the line' to be able to use the app.
OpenVPN for Android is an app to browse the Internet without any sort of restrictions. On top of that, it doesn't ask for many user permissions.
