This beta version of watchOS 4.3 contains bug fixes and improvements.
For more information, visit: https://developer.apple.com/go/?id=watchos-4.3-sdk-rn
The watchOS 4.3 software update also introduces support for Nightstand mode in portrait orientation.
Developers can download the watchOS configuration profile from the link below. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.