ZeroTier One for iOS allows you to join ZeroTier virtual networks as VPN connections on your iPhone, iPad, or iPod Touch.
Getting started takes seconds: Just tap '+', enter your network ID and name, and then click ‘join network.’ (Once a network is added you can also join it via the iOS VPN control panel.
It will appear there as an available VPN connection.) You can only join one ZeroTier network at once due to an iOS limitation of one VPN connection per network extension app.
ZeroTier One provides virtual network endpoint functionality for iOS devices.
ZeroTier creates secure peer-to-peer virtual Ethernet networks that work anywhere.