Using outside analytic sources in workflows and database

I am planning on using Google Tag Manager to implement all my tracking data, but I am also stating to think through the possibilities of leveraging that data within my app. The analytics engines I see plugins for are Google, MixPanel, Segment, Heap, HotJar, and Woopra. I assume that all of these are also available via API.

My Question:
Is anyone pulling analytics data into their app and then storing it locally and running additional workflows on it i.e. additional calculations and creating new things?