I went through all the iPhone apps that have a Watch supplemental app. (Yes, my head is about to explode, but I found some interesting apps!) It is still not clear to me which of these apps just use Watch to report the stats versus those that use Watch to collect the data. I don't carry my phone around a lot of the day though it is within 'earshot', and I am tired of being told to stand when I was just walking around or that I haven't taken enough steps. What Watch supplemental apps actually record steps themselves?