SichboPhone has gone into private alpha testing because it needs a re-write on account of Microsoft's UWP socket broker being too buggy to receive inbound notifications in a timely manner.
If you're interested in using it regardless of the socket broker bug, or if you're interested in alpha testing after a rewrite, shoot me an email - simon@sichbo.ca
If you don't care and want to use the UWP version anyway Launch the App Installer.