it always felt to me like the major innovation behind darksky was the clever exploitation of newly broadly available precision gps. prior to darksky, i'd look at the radar picture on my smartphone and the pin where i was to try and figure out when it would start raining, darksky seemed to just package this really nicely with visualizations and notifications.

(and yes, the visualizations were beautiful, but the real key was being able to see exactly where one was with respect to the radar picture and to be able to use already existing forward predictions of the radar picture in conjunction with precise gps to generate timeseries/events.)