I am surprised nobody has mentioned Datasette+Dogsheep by Simon Willison. From his excellent talk on "Personal Data Warehouses: Reclaiming Your Data" [1], "Dogsheep is a collection of tools for personal analytics using SQLite and Datasette". Simon's intended use of Dogsheep is to query/see what big tech knows about us. A more compelling use case for me is being able to full-text query my pocket, twitter and gmail. Add slack and text messages and I am happy to pay ~$100-200/year for this privilege.

[1] https://simonwillison.net/2020/Nov/14/personal-data-warehous...