Very nice Puntuado con 5 de 5 estrellas

OK. I made small investigation and found that this addon stand alone indeed does what is described, but addon "Scrollbar Anywhere" hinders. Anyway, thank you

Esta valoración es de una versión anterior del complemento (1.2.rev653.1-signed). 

Puntuado con 4 de 5 estrellas

Very nice.
But second right click doesn't return the image to original size - only reload does it.

Esta valoración es de una versión anterior del complemento (1.2.rev653.1-signed). 

That's odd, I have not experienced this issue :|