Quick Sketch - Image Editor for Jira

Quick Sketch allows you to create drawings and diagrams directly on Jira issue. You can also use existing attachment to draw on it, point or highlight something, or even drag/drop image from file or clipboard! After you done drawing you can then upload your sketch as attachment. There's also an option to add comment with your newly created sketch, for your convenience.

And besides standard drawing operations there are some additional tools that could be useful when working in business environment, like arrow for pointing at things on screenshots or highlighter for highlighting important parts.