The company has already clarified that they are only distributing the game through their official website. So its recommended not to download an app named as Fortnite or similar from the app store as searching for the game on Playstore will return this warning from Google “Fortnite Battle Royale by Epic Games, Inc is not available on Google Play.”
Check the device compatibility
Coming back to the game installation process, the first thing you need to do is to check the compatibility of your smartphone by going to ‘https://www.epicgames.com/fortnite/en-US/mobile/android/sign-up’.
Sign up for an invite
1.Open’ https://www.epicgames.com/fortnite/en-US/mobile/android/sign-up’ on your PC or Smartphone.
2.Then click on ‘Sign up for email invite’ button
3.It will redirect you to the Epic Games login portal. If you have already have an EPIC account, use that to login or you can use PlayStation, Xbox, Nintendo, Facebook or Google login credentials to create one