Is this similar to ZeroTier https://www.zerotier.com/?
ZeroTier's pretty damn cool, IMO: https://github.com/zerotier/ZeroTierOne
As a bonus, it'll route directly, instead of through an Open on server, etc.
I just wish they had an alternative to curl | bash. Something like Docker's install instructions, where you don't have to look through the install script to figure out what's going on inside sudo.
Android has an app, though I don't know whether the GUI part is open source.
So far, works great for me.