Quick Link
https://extensions.blender.org/add-ons/rigi-all/
Pricing
free
This is a free tool that speeds up adding Rigify bone types to existing deform armatures. You select appropriate bone chains, then pick the appropriate bone types. Can automatically rename bone chains to be symmetrical based on user configuration. Also has an option to add a DEF- prefix to vertex groups of a selected mesh.
Compatible with 4.0 and up starting with version 1.2, older versions compatible with 3.6.
