Greasy Fork

This script doesn't seem to be compatible with Firefox. Super bummed. (If it works for someone else PLEASE let me know.)
Marking this No Rating since it's not the script authors fault. I'd request they note it doesn't work with Firefox on the description page.

What exactly isn't working for you?

So I open an image in a new tab, then try one of the Ctrl shortcuts and nothing happens. I use GreasyMonkey on Firefox if that makes a difference.

Violentmonkey + Firefox works for me.

Thanks, yes Greasymonkey was the problem. I have updated the script, should work with Greasemonkey now too (and hopefully still work with the other addons)