Qikipedia - Instant Wikipedia summary cards on any web page
Algolia Places - Intelligent address autocomplete for any <input>
Six Degrees of Wikipedia - Find the shortest path between two subjects
Search Later - Save interesting article keywords to Google them later 🤓
Newsit - Find the discussion around the page you're looking at!
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.