Earlier today I received an email from a reader who was following up on my recent post about JoeZoo Express. She was asking if it was possible to browse existing rubrics in JoeZoo. Unfortunately, you can only share rubrics in JoeZoo if your school has the JoeZoo app installed domain-wide (it's free to do, ask your G Suite for Education administrator to do it). Once JoeZoo is installed across your your G Suite for Education domain, you will be able to share rubrics with your colleagues. The following video from JoeZoo explains how that works.
If you simply want to find publicly shared rubrics that were written in Google Docs or Google Sheets, you can do a Google search and refine your search to show results only from the domain docs.google.com or sheets.google.com. Here's how I structured a search for science project rubrics: science project rubric site:docs.google.com