Sken.io - The most advanced tools for tracking changes on websites.
Sketch - Professional digital design for Mac.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Finch for Windows - Make visual changes to any website. Immediately.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.