but it does not warn the user when the iPhone that it is linked to is at 20-10% (as far as I know)
This is correct.
There are apps that allow one to check the iPhone's battery via the Watch.
Power 2 ($2) is one such app I'm aware of, but the reviews aren't good. It's supposed to both warn of low battery and full charge.
It polls the 'Phone every 30min for it's battery percentage. A lot can happen in that time, but more frequent polling probably reduces battery life.
This feature, and an out-of-range, 'you're leaving your 'Phone behind!' notification, would be great wOS additions. However, I'd like the ability to set the 'low battery' to my preference (50%).








I am that Masked Man.
All you can do, is all you can do.
There’s trouble — it's time to play the sound of my people.
Your boos mean nothing to me, I've seen what you cheer for.
Insisting on your rights without acknowledging your responsibilities isn’t freedom, it’s adolescence.
I've been to the edge of the map, and there be monsters.
We are a government of laws, not men.
Everybody counts or nobody counts.
When a good man is hurt,
all who would be called good
must suffer with him.
You and I have memories longer than the road that stretches out ahead.
There is no safety for honest men except
by believing all possible evil of evil men.
We don’t do focus groups. They just ensure that you don’t offend anyone, and produce bland inoffensive products. —Sir Jonathan Ive
An armed society is a polite society.
And hope is a lousy defense.
You make me pull, I'll put you down.
I *love* SIGs. It's Glocks I hate.