Skitch is a free app that helps you communicate visually with friends, co-workers, and the world. Annotate images with arrows, shapes, and text.
Use Skitch to sketch something new, mark up maps, screen captures, or even a photo. Then save or share your Skitch annotation to help others see and understand your ideas. It features create smooth lines and scribbles to explain an idea, annotate maps, WebPages and screenshots, zoom and crop images, pixelate portions of an image, add highlights and draw attention to what matters, add text using special high-contrast coloring for readability, markup text with the highlighter tool, reposition and delete shapes, text and drawings at any time, and share your work with any application that accepts images.