Opis XDiagram is a flowchart maker and diagram software. This application allows to build any kind of Flowchart or Diagram. - Complex business processes and workflows are much easier to understand when presented in diagram form. The shape library of this app includes all the components you need...
Google Docs, of course, has a Drawing tool, but Lucid expands on it with some drag-n-drop features and other more advanced tools you would expect from fat-client apps. more information can be found on their website but if you search in the Chrome Web Store, you will find it...