Screenshot Bin - Generate website screenshots and thumbnails at scale, right from your app. Screenshots as a service.
Headers.me - Create social cover images that get you followers
Ui Thumbnail Generator - A simple way to generate thumbnail. For docs and demos.
Figen - Free post cover & background generator tool
FilePreviews - Thumbnails and metadata for almost any kind of file
Featured Image Creator - Stunning social sharing images for blog posts in seconds