A couple of Redditors have found that the newest version of Google Messenger (2.0.768) displays the option to enable Enhanced messaging' for a few Sprint devices. Among them, The Moto G4 Play, LG V20, LG G4, and a Nexus 5X. We tried to do the same with our HTC Bolt review unit, but the feature was a no-go. Likewise, some Redditors reported mixed results, so the feature isn't really available to all just yet. If you haven't heard of RCS (Rich Communication Services), it's basically the iMessage of Android. A new protocol for sending text messages that will succeed the outdated...
Source: http://www.gsmarena.com/rcs_live_across_more_sprint_devices_with_newest_version_of_google_messenger-news-22079.php