If you go to http://steemd.com/@picokernel you can see my json_metadata. Currently, I am using that field for another project to store profile picture information. In the future the use of json_metadata will be formalized, but for now its up to YOU the community members to decide what to use it for.
Jedi is an interface where you can play around and modify your json metadata. It is useful for developers to check there tools and users to correct their metadata. It features lots of little do-hickys to make your life easier including search, append, modify, and save. It should be capable of handling any valid json_metadata you can throw at it!
Source code can be found here: https://github.com/NateBrune/jedi
Thank you guys for the awesome community and I hope you enjoy.