It's been a couple of weeks since we saw a new iOS 11.4 beta, but Apple is changing that today.
Apple has released iOS 11.4 beta 3 to registered developers. If that's you, then you can download the new update by going to Settings > General > Software Update on your iPhone or iPad, or point your computer's browser to Apple's Developer Center on the web.
This iOS 11.4 beta includes features like Messages on iCloud, which will sync your iMessages in iCloud so that all of your iOS devices are up to date. It also includes AirPlay 2, which lets you play the same audio across devices in multiple rooms.
Apple hasn't said when it'll release iOS 11.4 to the public.
Also released today is watchOS 4.3.1 beta 3. It's unclear what, if any, new features might be included in this update. Instead, it may just focus on bug fixes.