1. Go to: about:config
2.Paste in: browser.altClickSave
3. Change to true

Doesn't work unless you do it.
Looks like the author assumed everybody knows it

THIS DOWNLOADS NOTHING

Absolutely amazing for saving lots of images. Shame it can't work around pages that limit downloads based on referrer or similar measures, I would love if it could save right from the browsers cache.

for some reason, it saves images without file's extensions

Easy and very effective. appears just as an option on right click. Thank you sir!

Does what the (German) name says, but I wish at least the spelling in the context menu would be correct, which is "Speichere" not "Speicher". Really hurts my yes. :-/

good

Absolutely not memorable name for the application. But this extension really nice and functional. Five stars for minimal persmissions. Like it. @Christoph Diehl, thank you man!

Five stars for minimal permissions.