Paste any number of domains or URLs, pick a search engine, and open each one as a site: search. Log the indexed-page count you see and it's remembered in this browser, so next time you can tell what changed.
Domains0 detected
Search engine
"Generate links" replaces the saved list for that engine with your current domains — handy for re-checking the next day. "Open all tabs" fires every search at once; some engines may show a CAPTCHA if too many land together.