I think they added a bit of polish/magic compared to what you'd get in a plain https proxy that you could setup yourself, since when visiting an HTTPS page it'l

I think they added a bit of polish/magic compared to what you'd get in a plain https proxy that you could setup yourself, since when visiting an HTTPS page it'll show the certificate information from the site that you're visiting, and not the one from the actual machine you're connecting to (the proxy). Similarly (unlike poorly setup proxies like Lenovo's Superfish) it also prevents connection to sites with invalid certificates. (I wrote the same comment in the gist)