You can get the chrome client from Github. That enabled one to circumvent the private beta until this announcement. There are no proprietary parts in the app store version.
Thus you should be able to make a native client just as well.
Thus you should be able to make a native client just as well.
Say, is there a way to go to your Github page [1] and grab a project that allows me to a) build a client (I think that's possible) and b) link clients just like the browser?
Could I create the world's ugliest native client, connecting to the Signal network using my (phone's .. hrm..) identity? Is that a scenario you support (in general, not with office hours..) or would consider if it isn't possible today?
1: https://github.com/WhisperSystems/