Here's another little script I hammered out for Canvas today.
With the new gradebook, you can set assignment statuses like "late" and "missing." This is helpful in the gradebook for on paper assignments (digital assignments are automatically flagged) but you can only change the status in the gradebook grid.
This is a hacked together script to add the same buttons to the SpeedGrader controls.
The easiest way to add this is by adding an extension called Tampermonky. This essentially allows you to run code on websites you don't have access to edit.
After installing the extension, click here to install the script.
Last step: click on the Tampermonkey Icon, choose Dashboard, and then click on SpeedGrader Status. In the editor, update line 14 with your Canvas URL.