HTTPS is a powerful tool that everyone should use because it helps keep sensitive browsing private at no extra cost to the people using it. But like most security standards, it has its own problems too. That little lock icon in your browser bar, which indicates the HTTPS connection, relies on a certificate “signed” by a recognized authority. But there are hundreds of such authorities, and as the EFF says, “the security of HTTPS is only as strong as the practices of the least trustworthy/competent CA [certificate authorities].” Plus, there have been plenty of news stories covering minor and even major vulnerabilities in the system. Some security professionals have worried about those least-competent authorities, spurring groups to improve on the certificate standards and prompting browsers to add warnings when you come across certificates and sites that don’t withstand scrutiny. So HTTPS is good—but like anything, it isn’t perfect.
The client is uniform across every device I have used (Windows, Android, and Amazon FireOS). I would like to say I was quite happy that ExpressVPN is one of the few VPNs (that seem trustworthy) that actually had a client in the Amazon App Store for the Fire tablets. No more need for sideloading, manual updates, or sketchy OpenVPN clone clients. At first the speeds weren't the greatest on the "Smart Location" server (New York). These speeds capped at about 12Mbps down and 10Mbps up. I have 150Mbps/15Mbps service. After hunting for other servers I found a few that provide roughly 60Mbps/15Mbps service throughout the US and Canada. DNS Leak tests were successful in that I am not leaking.