On December 5, 2017, Apple released the watchOS 4.2 software update, bringing the new Apple Pay Cash peer-to-peer payment feature to your wrist and adding other new capabilities.
watchOS 4.2 release notes

On December 5, 2017, Apple released the watchOS 4.2 software update, bringing the new Apple Pay Cash peer-to-peer payment feature to your wrist and adding other new capabilities.
Roughly a month after the last major Apple Watch software update, Apple has released watchOS 4.2, bringing support for Apple Pay Cash, among other changes.
Apple has announced that Apple Pay for Messages and the Apple Pay Cash card are officially launching today. Yesterday, some users had begun to see the feature appear, but now it is widely available for everyone who is running the latest iOS 11.2 update.
Yesterday's release of iOS 11.2 brought support for Apple Pay Cash, the new person-to-person mobile payment solution from Apple based on Apple Pay.
Apple released iOS 11.2 to the public in the middle of the night Friday evening. The software updates brings support for Apple Pay Cash, and faster wireless charging speeds, but this unusual release time indicates that iOS 11.2 has more likely been pushed to fix an issue with a bug that just started appearing for iOS 11.1.2 users.
For those in Australia, Woolworths customers are now able to add their rewards card directly into Apple Wallet and ditch the physical counterpart. They can then utilize Apple Pay to transmit their loyalty info over NFC at checkout to earn and redeem points.
Apple announced on Monday night that Apple Pay is expending to Sweden, Denmark, Finland and the United Arab Emirates.
During Sunday's Money20/20 Las Vegas event, Apple Pay head Jennifer Bailey gave a keynote presentation highlighting an upcoming expansion and some key stats while sharing more about what’s next for the company's mobile payments service.
Apple's mobile payment service in Spain has gained support for credit cards issued by the local bank CaixaBank and its mobile banking brand, called ImaginBank.
Eddy Cue, Apple's chief of Internet Software and Services and one of its most important negotiators with Hollywood producers and studios, has made some interesting comments regarding Apple's TV efforts during his trip to India.