We collected in this Github organization a collection of open-source plugins ported and tested on Elk for Raspberry Pi 3:
Every repository has an elk-headless-build branch with the changes to the original sources and a file README-ELK.md with build instructions and additional notes.
The binaries for the Elk Pi boards are available under the Release section, for example this is the link to the OB-Xd release:
We encourage contribution from everyone to the Elk Community organization! If you have a new repository that you want to publish there, drop us an email with your Github account and we’ll give you the permissions to do that.