PreFlight - Preflight is an Automated Web Testing tool. Allows everyone to automate Web UI tests.
CloudBrowser.co - A supremely flexible and reliable HTTP API that supports professionals and enterprise alike in the...
Videogram - Auto create interactive thumbnails (GIF card) of video
Microlink screenshot - Take a screenshot of any website
Thumbnail Test - A/B Test Your Thumbnails & Titles Live On YouTube
Webshot - Free and Open Source screenshot website service