Looks like more progress on a web UI frontend for JM using the RPC backend is being made here:
https://github.com/joinmarket-webui/jm-web-client
Those that can help, please do :)
@waxwing Yes, please do!
If someone wants to join the Web UI group or simply wants to follow along, have a look at the wiki: https://github.com/joinmarket-webui/joinmarket-webui/wiki
Another project for this also looks interesting:
https://github.com/manasgandy/joinmarket-gui