Catalog Butler

Products that arrived by CSV, migration or API have no category, and Shopify only suggests one while you create a product by hand. Catalog Butler reads the whole catalog, proposes a category for every product from the official taxonomy, shows you the entire change before a single word is written, applies it in bulk, and puts everything back with one click if you change your mind. Feed apps read this field; they never fill it. Fix it once and every feed inherits it.