flowi.es was a service once hosted on Heroku that appeared on https://flowi.es/.
Here's a screenshot:
and an archived version of the landing page: http://archive.is/vAI85
To run, it used a CouchDB instance with the design docs given in ./ddocs and run the crontab lines ./crontab, plus the Heroku dyno defined in ./Procfile.
There was also a helper server that just fetched each user rendered site from CouchDB and served it on http://*.on.flowi.es/ domains (yes, the entire sites were rendered on CouchDB using view and list functions). That was written in Go and, since it fitted in a single file, it's included here on ./web.go for brevity.
Anyway, you don't wanna run this.