Whatsapp - having whatsapp on your watch really helps during meetings where you can reply to your friends and colleagues discreetly. This almost made me want to get the sim versions of the galaxy watch.
Shazam - Its a really great tool for you to scan and receive info about the current music that’s playing. No more awkward phone shazam in public.
Google Home - a great way to turn off your lights and devices straight from your watch.