I'm looking for an extension that allows me to annotate the images that are uploaded to imgur by Stack Exchange.
This would mean drawing circles / 'drawing' text etc..
So, I made my own userscript Freehand Circles Drawing Tool. I've made a post at StackApps.
It allows you to view any image on any SE site, and start drawing on top of it. A button is added to each image called
edit. Clicking it converts the image to a canvas where you can draw whatever you want on top of the image. Clicking
save then makes a new image with the annotation and uploads it to imgur. It then updates the post with the new image.
You can therefore easily make images like:
(original image from here; everything red is by me :)