@r3v Sorry for the trouble. If you could grab any console logs and send those to me, it might help me troubleshoot.
Open Console, make sure your Mac is the selected device and search “Font Sync”. You can then try starting the app and hopefully it will show some sort of error
@r3v Does the icon appear in your menu bar, even for a moment?
Any message when you launch? (Crash reporting or error?)
What version of Mac OS are you on?