Apple has released the second beta of iOS 11 with a build number 15A5304i to developers and members of the Apple Developer Program.iOS 11 beta 2 contains bug fixes and improvements. Apple bought a number of features in the first beta of iOS 11 which was unveiled at WWDC 2017 .
iOS 11 beta 2 is available for download to registered developer’s via OTA over-the-air from iOS settings app running previous beta or you can also download iOS 11 Beta through Apple’sonline developer center and Apple Beta SoftwareProgram whereas iOS 11 Public beta will be available soon.
Along with that, Apple also released Second beta for macOS 10.13, watchOS 4 and tvOS 11.
How to Update Second beta version;
In case of mac, macOS Sierra 10.13 beta 2 can be installed through Mac App Store’s Updates tab.
For Apple TV, tvOS 10.11 beta 2 can be installed in Settings → System → Software Updates → Update Software.
And for Apple Watch, watchOS 4 beta 2 can be installed with the Watch app on your iPhone by tapping My Watch → General → Software Update.