Apple has released iOS 12 public beta 3 for download, along with tvOS 12 public beta 3, while the third beta of macOS Mojave was released yesterday.
iOS 12 Public beta 3 comes in as a 579.9 MB download for iPhone X, which corresponds to the fourth beta for developers, released yesterday.
Public beta testers can update their iPhone or iPad to this latest build by going to Settings > General > Software Update and tapping ‘Download and Install’.
The Apple Beta Software Program is available free for any user to try and test pre-release software, but should only be considered for your secondary devices (#becausebetasoftware). However, in our tests, since the second public beta, it’s been quite stable on an iPhone X.