Many TV networks have their own mobile apps or websites for watching on-demand content, but they almost always require a cable subscription. Most of them use 'TV Everywhere,' which allows people to login with a vast amount of service providers. As a new support document points out, YouTube TV now works with TV Everywhere.

This means that you can login with your YouTube TV account on just about any site or app that requires a cable subscription for watching content. For example, if you go to the desktop site for Disney XD, 'YouTube TV' now appears as a login option:

This seems to already be live for every site/app that uses TV Everywhere. I tried a few other networks, like MSNBC and Fox News, and they also showed YouTube TV as a login option. You can find the original support document at the source link below.