If you want to use Sync, be my guest, I’m glad you’ve found an app you like. I genuinely don’t care what app anyone uses. Also, if you want to share your love of an app with others, feel free to do that too.
But - and try to hear this - hijacking a thread which is about making sure Lemmy gets developed (without which your app won’t work) and supporting instances (without which your app won’t work) to say how much you love your app is beyond crass.