I built one for myself, sqlite + apache superset. I basically did that because over the years I had switched devices from different companies and I used to use endomondo which was shut down. I wanted to have all my data in once place. It does require me to export data from device and use my import script once a while, however works for me.
> Congrats, you sold some data that says I'm fat, out of shape, and don't like riding my bike on busy roads.
I can only imagine anyone buying the data does so only if they believe they can make more using the data. I don't think I know of anyone doing this now (not sure if there is regulation preventing this), but its not hard to imagine a eventuality where your health data/work out information can be used by your health insurance provider.
Imagine a scenario, your bmi is higher than normal and is trending higher in the past few months, so that increases your risk for x and hence your insurance premiums go up. Would you care then?
