There is not needed to have the root access, because the VPN tun device is handled with the VpnService API introduced with Android 4.0 (ICS).
The in-app purchase authorization is used only for voluntary donation to support the app development.
* Static key password protection
* Fingerprint authentication (Require at least Android 6.0)
* Auto connect on boot
* App filter (Require Android >= 5.0)
* Android 7.1 dynamic shortcuts
* Import/export openvpn configuration
* Import pem, der, pkcs12 cetfificate formats
* Support for certificates in KeyChain
* IPv6 support
* Support for HTTP/SOCKS proxies
* Support for customized HTTP headers
* Backup/restore configuration
Join to the OpenVPN Client community (https://plus.google.com/u/0/communities/115310249264827900069) and you will able to try the beta versions, read the news about the app and much more...
Some hints to test the app:
* To import a openvpn configuration file, copy the ovpn file on the device memory and put in the same folder any external certificates/keys files. Then start the app, tap on "+" button in bottom right corner and choose "Import VPN profile". After the import, the files can be deleted.
* If something goes wrong, check the log. You can see the log by tapping on the vpn name, and so on the LOG tab.
* If the log has errors like "ERROR: Cannot open TUN/TAP" or "Tun device open exception: java.lang.NullPointerException", please try to reboot the device.
* If you have the access on the server side, check the log also on this side.
* Maybe your configuration is not compatible with the last version of openvpn, so try to set the option "Use old stable OpenVPN 2.3.2" in the "Options" section.
* If you cannot resolve the troubles, please send me a e-mail to firstname.lastname@example.org, I will contact you at soon as possible and I will help you to solve the problem.
The new app filter feature can be used only on Android versions greater or equal than 5.0 (Lollipop). This feature allow to choose which apps are allowed to use the vpn. The apps not allowed will use networking as if the VPN wasn't running.
This free version doesn't has the following features:
* Tap device support
* obfsproxy support
* scramble options support
* Port knocking
* Auto connect on connectivity up/down
* Tasker/Locale plugin
* Android 7.0 quick settings tiles
If you want also these features, you can buy the full version.