It basically allows you to watch every TV show and movie ever made for free. After you buy the box of course.
I got turned on to it from my old lady's sister when I was trying to watch the last season of shameless without having to pay for showtime.
She has an amazon fire tv stick that was jailbroken and let us borrow it. It was ok but it was slow as dick and after I gave it back I looked into what other options there were out there that were faster.
The app is called Kodi and it basically lets you watch pretty much anything without a cable provider. All movies and TV, sports, PPV, etc.
Out the box it needs some work to get all the sports and PPV but for movies and TV and shit it's ready to go.
I only got it a couple days ago but I already watched 2 movies that are still in theaters for my kids and I also watched Star War Rouge One. Watching the NFL game right now in 1080p as well.
There are a lot of jailbroken things out there but I got a x96 Android tv box 2x16 with Kodi and I love it. The fire stick is garbage but it will suffice for now.