What is ‘Fortnite’ and why are you suddenly hearing about it everywhere?

Right now, Fortnite is having a moment. Made by Cary-based Epic Games, Fortnite is the mobile version of Fortnite Battle Royale. 

And after last week's release of the IOS version, it has emerged as the latest gaming sensation. If it's not quite up to the level of 2016's Pokémon Go craze, it's getting there.