A free app for Android, by Digital Software Group.
What is OpenConnect?
This app is an SSL VPN client for Cisco AnyConnect and ocserv gateways.
There are a number of key features to this tool, such as app filtering for Andoid 5 and up, connection through a single click, keepalive features that put a stop to unnecessary disconnections, and a lot more.
However, in order to use this app, there are also certain requirements. You have to have an account on an appropriate server, and your device must be an android 4.1 or higher with working VpnService, as well as tun infrastructure.
This is available on Google Play Store.