Every little counts, especially if you make it a routine part of your day.
Even on days that I can't get a workout in, I'll throw a few pull-ups in on my bar just for good measure. Sometimes I'll do half a workout. Sometimes I'll just do a quick set before I leave the house.
Every little bit helps. No excuses not to move your body for a minute per day. You'd be surprised how far it goes.
Yeah I think you'd need an iPhone for it to work. I think any smart watch would work fine though, just make sure that it can play music offline. For the apple watch I just tell it which albums to download to the watch then they're available to listen to even if it's not connected to my phone (or wifi).
I basically just use mine for running, the only other feature I like is that apple pay is slightly easier to pay from my watch vs pulling out my phone.