OpenVPN Connect, the “official” OpenVPN Inc. app is designed to be user-friendly for VPN users who have little technical expertise. This means that it is less equipped than the openvpn for android which is designed for more advanced OpenVPN users.
Openvpn for Android Openvpn for Android, a free and open-source client developed by Arne Schwarzbe, allows you to connect with any VPN service that is compatible with the OpenVPN protocol. It’s a great choice when your device isn’t compatible with pre-configured “off the shelf” VPN apps that are available on the Google Play Store. The setup is pretty straightforward. You will need to import the VPN profile files. (The configuration files are named.ovpn). These files can be downloaded from your provider’s site or via live chat support.
After you’ve imported your profile, tap on the server to connect. Once connected all Internet traffic is sent through a secure tunnel, and directed to the chosen server by the app. The Status tab allows you to examine your connection’s information and status. A kill switch is always enabled by default, and it will shut down your Internet connections when the VPN tunnel drops.
The application offers a per-app VPN as also an option that is always on that automatically establishes an VPN connection every time the app is opened and continues running even after your device has shut down or switched networks. The latter however requires Android 7.0 or higher, and could drain your battery more than usual.
http://openvpnandroid.com/10-reasons-why-to-choose-norton-antivirus/