Three to six months ago I found the flowchart software called draw.io. I have lauded it for it’s easy drag / drop behavior for generating rich flowcharts, schemes, and UI mocks. The application is designed to sync to a Google Drive (google doc api) account and offers all the fun sharing & collaboration features that I have come to expect from a cloud application. I have not had the opportunity to try out the Jira or Confluence integration yet–so I cannot give any advice or review there.
Diagrams generated can be exported in a variety of image formats (JPG, PNG, etc), SVG, XML and PDF (which I haven’t tried or found a use for yet), or HTML–which generates a static webpage that can be used on desktop browsers (see the following examples):
I love this tool.