Announced today as part of Nintendo's E3 2018 Direct presentation, Fortnite is coming to Nintendo Switch. The port is out today, and only contains the game's Battle Royale mode, but will allow you to jump in for free and play probably the biggest game in the world right now.
Fortnite coming to Switch has been known for a little while, as it was rated by the Korean ratings board, then dataminers found the game's Switch icon, then the game's store page leaked ahead of its reveal today.
You should be able to grab Fortnite on your Switch at 6pm today. It takes up around 2.5GB of system space to download according to the leaked store page we saw earlier today.