PPTP vpn is not available now but we still can use Open vpn and L2TP/IP Sec vpn tunnels in these operating systems.
This kind of vpn connection is very secure and reliable.
Below you can find simple step by step guides how to use VPN in iOS 10.
VPN setup Guides for iOS 10
To make a new vpn connection in your iOS device you need to do the next:
1. Go to Settings > General > VPN
2. Click Add VPN Configuration. Select L2TP VPN and click Back
3. Input you VPN account data – server, account and password. You get these data from Sahrzad service in the e-mail after ordering vpn. Fill the Secret field – secret (small letters)
4. Tap Done to save the settings.
Once you have created vpn connection you can switch it
on and
off on the main settings screen.
http://sahrzad.net/blog/using-vpn-apples-ios-10-mac-os-sierra-whats-new/