Browsershots - Browsershots makes screenshots of your web design in different browsers.
Artboard Studio - Online graphic design app mainly focused on product mockups.
CrossBrowserTesting - Browser Testing made simple! Run automated, visual, and manual tests on 1500+ real browsers and mobile devices. Test more browsers, in less time.
Canva - Canva is a graphic-design platform with a drag-and-drop interface to create print or visual content while providing templates, images, and fonts. Canva makes graphic design more straightforward and accessible regardless of skill level.
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
Snappa - The perfect graphic design tool for digital marketers.