Webchemy

Webchemy is a free cross-platform web-app for creating idea sparking sketches. Based on the desktop application Alchemy, Webchemy takes some of its drawing tools and brings them to the web. Features: - Lots of different drawing modes - Symmetry (vertical and horizontal) - Save as PNG or SVG - 10 Undo/Redo steps (even after clearing) - Color palettes and Color Slider - Eyedropper tool - Touch support - Zoom Webchemy runs on many devices. You can also use it on Android and iOS in your browser.

Screenshots from Chrome Web Store