New Gadget - Mark Files used in a Wiki or Wikidata
Problem: In the different maintenance categories (~ 650,000 images without category; ~ 50,000 categories with infobox not connected in Wikidata) you could use the connected images to set categories to a Wiki or Wikidata faster or then connect them to Wikidata. At the moment you would have to open every picture and scroll down to see this state.
Who would benefit: people who are involved in maintenance; like "Wikidata infobox maintenance" or "Media needing categories"
Proposed solution: I would suggest to have a new gadget created, which, if you are in a category, marks the images that are connected to a wiki or wikidata. (Maybe, if it is technically possible, only pictures that are in namespace "0"!)