"What does Google know" (WDGK) reads the zip file from the Google take out and shows some stats from your personal data. All this is happening locally on your computer. Therefore, full privacy is guaranteed.
Go to WDGK to check it out!
So far I've only developed some graphs on the browser activity. I'm planning to do more analyses with the browser history and focus next on the location history. Feel free to contribute your analysis.