"Gatsby is a free and open source framework based on React that helps developers build blazing fast websites and apps" (from gatsbyjs.org).
As a Blockstack app developer, Gatsby got my attention because the framework focuses on static site generation and integrating data source easily. There are plenty of libraries to build apps with Gatsby, some to bootstrap apps with a certain framework, others to integrate different sources.
I came across the jamhackathon starter library that uses the Netlify Identity System. I don't know much about that but I wanted to replace it with Blockstack identities. The result is a Blockstack starter library:
You can try it out https://hungry-swirles-57c2cd.netlify.com/