Avast SecureLine and Avira Phantom VPN are run by antivirus companies as complements to their primary businesses. These services are also limited to Windows, Mac, iOS and Android and don't work without client software. But they offer few features, have a couple of dozen servers at most and don't let you pay anonymously. However, the companies are known quantities, and the services are handy for occasional travelers.
They even offer the most generous simultaneous connection count, with six simultaneous connections through their network, where everyone else offers five or fewer. NordVPN's network isn't as large as some of their competitors, so if you're trying to obfuscate your tracks, you might want a company with more servers. Otherwise, this company is clearly providing a winning offering.