The app lets one choose from servers in five locations: the US, Canada, Germany, Singapore and the Netherlands.
The app has a Wi-Fi test tool that will scan the network to which one is connected. If any weaknesses are detected, it will advise connecting via the VPN.
The test tool scores a network from A (secure) to F, which means the network is insecure and you should proceed with extra caution.
The VPN services are being offered by SurfEasy, a company that Opera bought last year.
The app collects anonymous data which Opera makes available to third parties.
SurfEasy chief Chris Houston said: "We have incorporated a Viking in the app. The Vikings didn't care about borders, and they sure weren't afraid of public Wi-Fi! And with the right tools, they stayed safe. The Opera VPN app can help unlock online borders and is the closest thing to a Viking shield today’s mobile users have for virtual self-protection."
The Android-based service supports English, Arabic, French, German, Indonesian, Japanese, Portuguese, Russian, Polish, and Spanish.