Apple has detailed a few features in Tuesday's iOS 11, and has noted that the feature that allows for person-to-person money transfers, dubbed Apple Pay Cash, will arrive in an update to iOS 11 and watchOS 4.
In the announcement made on Monday heralding the imminent arrival of iOS 11, Apple notes that the feature will not ship until an update "coming this fall." It is not clear is this is a delay, or if Apple didn't plan on rolling out the feature with the launch of iOS 11.
[Update: The launch of Apple Pay Cash has not been delayed. Apple originally introduced Apple Pay Cash as an upcoming feature that would be added to iOS 11 after its initial launch, similar to the way it originally launched Apple Pay itself.
In 2014, the company initially projected that "starting in October" Apple Pay "will be available" to users in the United States, a week prior to the mid-September launch of iOS 8. It was indeed made available after the launch of iOS in a free software update delivered in October as planned.]
Apple Pay Cash payments will be initiated through a dedicated app within Apple's Messages in iOS 11. The service will integrate with Siri's new machine learning capabilities, offering suggested amounts to send based on the context of conversations had within messages.
Once money is transferred, it will be available in a prepaid "Apple Pay Cash" card through partner Green Dot. The cash card can be used to make Apple Pay purchases in stores, in apps, or on the web, or it can be transferred to the user's bank account.