Etsy bulk files have the same holes. You do not need an app.

Blank SKUs, $0 prices, listings with no IMAGE1, two rows sharing a SKU. Export or download your listing CSV and check it in the browser.

Open the CSV check

How

1. Etsy Shop Manager → Listings → tools that export a CSV (or your bulk listing template).
2. Open csv-check.html and drop the file. Nothing is uploaded.
3. The checker looks for SKU, TITLE, PRICE, and IMAGE1. Duplicate SKUs are flagged.
4. Fix the rows that cannot sell. A ranked Monday list of 20 is the Store Audit (USD $149) — email the same CSV to info@shopgaps.com.

ShopGaps is not an Etsy app and does not connect to your shop. WooCommerce merchants who want an on-site plugin can use Catalog Audit.