Fortnite game originally came to Android only on Samsung devices, Galaxy Note 9 and Tab S4 owners. But if you’re addicted to Fortnite and own a Gear/Galaxy smartwatch, you might be interested in a Galaxy Fortnite watch face that’s available on the Galaxy Apps store.
You can download the Fortnite watch face from the Galaxy Apps store on your connected device. If you’re viewing this page on your phone, click this link to directly open the Fortnite watch face download page. Otherwise, just go into the watch section of Galaxy Apps and search for Fortnite. The first result should be the watch face.
There are also a couple of other Fortnite watch faces, but those seem to be exclusive to the Galaxy Watch for now. You should see them in the Galaxy Apps store when you search for Fortnite.