Six days after the release of the first public beta of iOS 11.2
This is a new service that lets you send and receive money via iMessage. It is a direct matter from person to person. Once you've installed the latest beta version of iOS 11.2, you can use it by tapping the "Apple Pay" button in the "Apps" section of messages.
You can make payments within a conversation simply by asking for money. Or you can send someone money after typing on the message requesting it. Currently, Apple Pay Cash is only available in the US and you need to set up two-factor authentication for your Apple ID for it to work.
Any debit or credit card you've added to Apple Pay can be the source for the transfers. Apple says it will not charge a bank transfer fee if you use a debit card to fund pay cash, but there will be an "industry standard" charge for credit cards. The company does not explicitly say how much.
When someone sends you money for the first time, you will choose to receive a new virtual Apple Pay Cash card. The virtual card is needed for Apple to make the transfers immediately. You can spend it immediately via Apple Pay Cash. However, the virtual card only works to send money or pay via Apple Pay.
You can also send money directly from the Contacts app by selecting the $ symbol under a person's name. Alternatively, you can ask Siri to send or request some money.
SOURCES: TECHCRUNCH.COM GSMARENA.COM MACRUMORS.COM
WIRED.COM FIRSTPOST.COM ANDROIDCENTRAL.COM