It's been exactly two weeks since Apple released the second developer betas of iOS 12, macOS 10.14 Mojave, watchOS 5, and tvOS 12. Today, the company released the third builds of all except for macOS 10.14 Mojave, although that could show up later on today.
iOS 12 build 16A5318d still has a bunch of known issues, but it does have some notable fixes. Apps like Skype, Twitter, and Taobao that might have crashed previously, will now work. Unfortunately, Netflix may still crash when downloading videos, although from our testing, the video resumes downloading upon relaunching the app. Also, Fortnite might crash during use.
The watchOS 5 build 16R5313d release notes seem to show more new issues than resolved ones. For instance, changes to contacts might not sync right away, or all of your contacts might just disappear on your Watch. Phone and FaceTime might crash as well, when hitting the call button on a contact.
It's also worth noting that your Apple Watch might crash when pairing with your iPhone for the first time. You'll want to keep this in mind if you're thinking of doing a reset of your Watch. Remember, there's no easy way to roll back to watchOS 4.
tvOS 12 build 16J5313d's only new issue is that this might unexpectedly turn off "Share Apple TV Analytics", which is hardly a deal-breaker. Also, you can just turn it back on. There are, of course, some older known issues that haven't been resolved, such as that some icons might go missing from your Apple TV's home screen.
With the exception of watchOS, these builds will likely arrive for those on the public beta tomorrow. The general public will get these updates in late September.