SQLBin is a simple, fast, lightweight, efficient, AGPL-licensed, single-binary, boringly-named and equally plain-looking multi-user web interface for running and sharing queries against a PostgreSQL database, written in Crystal.
See the SQLBin homepage for more information.
A live demo can be found at sqlbin.vndb.org.
There's no (binary) releases at this point. If you think you have an interesting use case for this project, let me know and maybe it'll help me get motivated to turn this into a proper project.