
Lucidchart
Online diagram and flowchart software that supports Microsoft Visio import and can work on any operating system.
PhotonJam's Lightbox is a light weight web based drawing app to easily create diagrams, flow charts, icons and doodles.
LightBox is an online drawing tool that simulates the features of an artist's light box that helps you trace images to create digital hand drawn art, diagrams, flow charts and more. You can add your own art or edit and use existing symbols in SVG format. The integrated drawing app also gives you the ability to free form draw anything you like to create something truly unique. And it's fun!
drawing diagrams flowchart diagramming sketching diagram sketch