I wouldn't call this a must have app as much as a glad I have app
Watch Reminder.
Though I found it on my phone and not watch it isn't compatible with my phone . It is a true stand alone for Android Wear .
If you , like me , want a daily pill reminder this is a way to unplug from your phone in yet another way . It can be used for any type of reminder but I choose to use mine to remind me to take my meds each morning . You'd think after years it'd be automatic but in my case it still hasn't become automatic .
The free version doesn't allow multi day timers ($1.99 1 time for premium upgrade) but for 1 time or just to try before buy you'll be able to explore the app to see if it's for you .
There's not a bunch of bells and whistles to setting things up , no special notification ability but what it does it does well on my Galaxy Watch 4.
Sliding left, right , up , down is how you navigate and tapping the back button on your watch is how you escape after naming the reminder .
Time will tell if it's a battery hog and I'll post back if it is one .
Here's some screen shots .
Darth Mode 10+