Don’t know why, I installed this new extension in FF 3 but I’m suspicious as it downloads all the jpegs from various web pages without even scanning them for viruses and spywares. Is somebody interested to give us an opinion about that extension? ???
I do not use it as I think I don’t need it 
It’s a fantastic extension. Really improves pictures viewing. I did a bit of Google search and found elements that were infected by worms while using Piclens. It’s like using FF, should check what you use it for. Seems to be also available as an add-on for IE. Too good to be true!!! 
I love it. 