Fortnite is now available on Android without the complications of invitation. In the past, you needed an invitation in order to play Fortnite on Android, now you can download it to any Android device for free, without waiting. Here is the official site for download.
Here is the list of supported devices to make sure yours is there. Also the system requirements are here:
- OS: Recommended Android 8.0 or higher, 64 bit
- RAM: Recommended 4GB or higher
- GPU: Adreno 530 or higher, Mali-G71 MP20, Mali-G72 MP12 or higher
For security reasons, make sure to install through the official site.