Samsung has released a new video in support of Google’s #GetTheMessage campaign which calls for Apple to adopt RCS or “Rich Communication Services,” the cross-platform protocol pitched as a successor to SMS that adopts many of the features found in modern messaging apps… like Apple’s own iMessage.
Google’s RCS is as proprietary as iMessage
But it is at least available for Apple to implement if they do choose, unlike iMessage.
No, its not available. There is no FOSS RCS app, because its not available
Signal is also available on every platform, you don’t need to use whatever chat app your phone’s manufacturer wants you to use, it’s your choice. And Signal is probably the best choice right now.
Looks like it’s not open sources, yes.