Cross-platform voice chat has arrived on Fortnite in the Party Hub section on mobile devices. It will allow players to communicate with friends and party up even when they aren't playing the game. Voice chat is the highlight in this app and players will be able to talk to their friends on any platform also while the game is downloading.
This feature arrives in Fortnite since Houseparty was acquired by Epic Games back in June. Since it's cross-platform, you can chat from your mobile devices with fellow Fortnite players on a PC or gaming console. If you're ready to join a game, you can continue talking inside Fortnite on any of the platforms. All you need to do is while you're in Party Hub, tap on 'Transfer Voice to This Device' button, select the device and you're good to go. It works the other way round as well, so if you were chatting on the PC or console, it can be continued on your mobile device.
Party Hub currently only supports voice chat while text chat is under development. According to The Verge, Houseparty's core feature is video chat but there's no indication whether it will be added in the future. Although video chat isn't really an important feature in a game when you're only talking to your Fortnite buddies about partying up. It's, of course, only available on mobile devices and it continues in normal chat on the PC and consoles.
Players will have privacy control where they can enable the lock icon (button over the avatar icon) so that others can't join your party. They will require an invite from you to be able to join. Enabling the lock icon will also prevent others from voice chatting with you and joining your party. For those who don't play with others at all (not the way you should be playing Fortnite), you can set your party to private that will turn off Party Hub.
The voice chat update to Party Hub is currently rolling out to Android and iOS. Epic Games has posted a long list of FAQs to help users better understand the capabilities of Party Hub that you should definitely check out.