Addon for Blender 2.80 for customisable rigging interfaces
Download repository as ZIP, then in Blender: Edit -> Preferences -> Add-ons -> Install... -> select blender-rig-ui.zip
If it doesn't work check the addon folder in Appdata/Roaming/Blender Foundation/2.80/scripts/addons is called blender-rigui (latest release)
https://github.com/Lateasusual/blender-rig-ui/wiki/Setup
Addon is very much WIP, regular updates on the way :)
^ That line was a lie, this hasn't been updated in 2 years. It's still partially functional in modern blender versions, but i'm not actively maintaining it.