First of all, I can't even count how many times I take phone out of my pocket just to see notification. If I have any text, missed call, email or anything. I can't even keep my phone on vibrate, because I then I forget to turn the vibrate off and when I am in a meeting and I feel embarrassed when it vibrates. Anyways, so having a smartwatch just for the notification, would be SOOO much convenient. Just raise your wrist and you are good to go.
Then when you listening to music, radio, you want to forward a track, change album. Its just there. You don't have to take out your phone.
If you want to record something just launch it from smartwatch and recorded file is saved in your phone.
Apps: Weather apps, location service (tells you exactly where you are), turn by turn navigation when you are on foot.
This is just fraction of things that can be achieved with such device. Honestly if you think about it, its a game changer in many ways if done right. They really have to approach this as a companion device and not a stand alone device. I feel like Apple is on a right track, Galaxy not so much.