Apple has released watchOS 4.2 to the public, this software update is available for all Apple Watch models and includes support for Apple Pay Cash. Apple Pay cash allows payments up to $3,000 to friends with Apple Pay Cash.
On the Apple Watch In Messages, Apple Pay Cash is a new quick action just below Scribble that you see when replying to an iMessage. Apple Pay Cash was introduced in iOS 11.2 on the iPhone and is available in the US only at the moment.
Other changes in this update are:
Adds support for \homeKit sprinklers and taps in home
Adds support for a new workout type for third party apps to track distance, average speed, number of runs and elevation depended for downhill snow sports with the Apple Watch series 3
Resolves an issue where Apple Watch would sometimes restart when asking Siri about the weather
Fixes an issue where scrolling was disabled for some users
Resolves an issue that prevented simultaneous timers or alarms from being dismissed independently