The latest version of the app, which you can download from the App Store now, has built-in support for the iOS Picture in Picture (PiP) feature. This enables you to stick a video chat into a little window that stays on screen while you do other things on your phone. It's something Apple's own FaceTime has had for a while and it's a really useful feature.
Although the support is baked into the app, WhatsApp is rolling out the feature over the next few weeks so if you don't have it yet, don't worry. It's coming, alongside a few other useful tweaks.
What's new in WhatsApp for iPhone?
If you've already updated WhatsApp recently, this is a new update. The last one was primarily about bug fixes and security updates. This one's about adding more functionality.
The other new features in the app are a little less exciting but they're still handy to have. You can now add captions when you're sending documents, and there's support for longer group subjects and descriptions so you can wax a little more lyrical when you're organising your chats.
You can also create personalised avatars, which you can then use for stickers and profile photos. You'll find that feature in Settings > Avatar.
As with Picture in Picture support, these new features will be rolled out in the coming weeks. They'll also be rolling out to Android users as they're not based on operating system features, as PiP is.