With this app you will able to connect to any OpenVPN server and SSTP VPN servers.
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.
* OpenVPN TAP device support without root permission
* OpenVPN VLAN 802.1Q support
* OpenVPN Obfsproxy support (obfs2/obfs3)
* OpenVPN scramble options support
* OpenVPN Static key password protection
* Import/export OpenVPN configuration
* SSTP EAP-TLS support (Authentication with certificates)
* SSTP EAP-MS-CHAPv2 support
* SSTP MS-CHAPv2/CHAP/PAP support
* Fingerprint authentication (Require at least Android 6.0)
* Port knocking
* Connect on demand
* Auto connect on boot
* Auto connect/pause/disconnect on WiFi/Mobile/WiMAX up/down
* App filter (Require Android >= 5.0)
* Tasker/Locale plugin
* Android 7.0 quick settings tiles
* Android 7.1 dynamic shortcuts
* 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 VPN Client Pro community (https://plus.google.com/u/0/communities/110345276211484288641) and you will able to try the beta versions, read the news about the app and much more...