OpenVPN Connect is the «official» application from OpenVPN Inc. and is intended to be more user-friendly for VPN users with little technical experience. It is, therefore, less equipped than the openvpn for android that is targeted at more advanced OpenVPN users.
Openvpn for Android is a free and open source client made by Arne Schwabe which allows you to connect to any VPN service that is compatible with the OpenVPN protocol. If your device isn’t compatible the pre-configured VPN applications that are available in the Google Play Store, this is a great alternative. It’s relatively simple to set up. You’ll need to download the VPN profile files. (The configuration files are named.ovpn). They can be downloaded from your VPN provider’s site or by contacting live chat support.
When you’ve imported a profile, simply tap on one of the servers in the list in order to connect to the server. Once connected it will ensure that all Internet traffic is sent through an encrypted tunnel and then directed to the server chosen by the application. You can check the status of your connection and its details on the Status tab. The kill switch is enabled by default. It will shut down your internet connection when the VPN tunnel is dropped.
The app provides a per application VPN as also an option that is always on that automatically establishes a VPN connection whenever the app is opened and continues running after your device has shut down or switched networks. However, the latter requires Android 7.0 or higher and may drain your battery more than usual.