Yes, I have heard about it, in fact, I use to consider myself as a big fan of adult gay tube sites. Tube site works with a principle similar to the internet sensation the Youtube. We all know youtube is a social media platform that gives us a platform to share our exciting videos and contents. Same way, adult gay tube sites are also the platform to share all the adult gay videos and stuff.
On an adult gay tube site, a user can create a free account simply with his email, share his favorite videos (even of his own) using his account, explore and watch what other users are uploading, rate their videos and even follow the users they like to follow.
Some of the top adult gay tube sites at the moment are ManHub, GayTube, HotGayList, and BonerTube. They have a lot of users with a lot of videos on their site.