VPN app/website

I want to get a vpn app built for ios/android, windows, and a website. I want people to be able to login pay for subscriptions and connect to the vpn I will manage getting all of the vps servers set up is all I need a developer to do is impliment it into apps and a website and make it connectable. I want the apps and website to look nice and be very user friendly. I will give more details upon contact from developer I have a document typed out that breaks it down very well for the developer on what is wanted.