RCS is considered a rough parallel to Apple's iMessage with WiFi chatting, high-quality photos and videos, typing notifications, read receipts and better group chat controls. It doesn't have end-to-end encryption like iMessage, though. As with SMS, your conversations aren't particularly secure.

There's still a long way to go before RCS is truly universal, though. Google reiterated that the technology is only available beyond the US in France, Mexico and the UK, and it's still "working' to bring support to both more regions and third-party apps. And of course, Apple isn't in a rush to support RCS. Although the finished US rollout is a major milestone, it's only one step among many.