As someone who dislikes being tracked, I find it disconcerting to have this level of data stored in 3rd party services, but joining up multiple services to give one coherent picture is cool. How cool is questionable, trying to correlate health data with location data is going to give a strange picture, and I question how relating health data to weather is useful. (Do I have lower blood pressure on rainy days?)

Forgive me for I am being sceptical. The might be some insight here I have not considered, but I'd feel a lot more comfortable if it was all self-hosted / self-collected data.