Would be better integrated as part of the default Messages application by creating a Telepathy connection manager, that way it could theoretically also work on desktop applications like Empathy and whatever else makes use of Telepathy as its backend. Separate applications are ******ed if the option to have everything integrated exists. A native Sailfish OS application, not integrated in Messages, fixes nothing with regards to usability, the most it would be able to do would be to remove the need for the proprietary Android compatibility layer.

edit: why is 're​tard' censored, jesus

edit: also, unfortunately it isn't particularly easy to find whether anyone is actually working on something like this, considering the search results for "telepathy signal" aren't very technology-related, to put it lightly.