Two things:
1. There is no iWatch. There is, however, the Apple Watch.
2. It does not require "constant charging". My series 2 Apple Watch, like a smartphone, can go two or three days without a charge. I have gotten into the habit of attaching the magnetic charger to the back of my phone when I begin to get ready for work. By the time I have brushed my teeth, shaved, showered and gotten dressed, my watch is back to 100%.
My Apple Watch probably saved my life. A sleep monitoring app showed I was getting no sleep and, after going through a sleep study, it was discovered that I have obstructive and central sleep apnea, to the extent of it being life threatening.
The other extremely useful feature has been the ability to text and take calls without pulling out my phone. I can just tap my watch and talk. Very handy.
My Watch also keeps track of my physical activity. Having the report sent to my doctor has verified my assertion that while I am overweight, I am very physically active, which is leading to investigations as to why, on a 1600 calorie a day diet, I do not loose weight.
can go two or three days without a charge.
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As I said , useless as a watch ,, my watch goes about 4 years on a $0.99 battery.