Link : http://shutter-project.org/
Though Solus has 'Screenshot', after capturing a screenshot, we need to open another tool ( like gimp ) to edit them, shutter makes this process a one time effort, allowing us to edit the screenshot before saving.
It is still a great tool, which got an update in September 2017 http://shutter-project.org/2017/09/after-a-long-time-a-new-bug-fix-release-0-94/
Especially easy editing/painting on top of images are a very good feature.
I looked into it. Seems like it would be a pain to package. There is no build system from what I can tell. I'm not even sure if the tarball that they call their source code contains the actual code.