Forgive my poor English..... I hope this app works so simply that one long press(instead of double press) of power button will pop-up the menu.

And the menu has a screenshot option. You know, common android device use key PowerButton+HomeButton combo to achieve that.

As far as I could see, the Extended Power Menu could add a icon on the pop-up menu, when user press the icon, it will save the screen content the user want into the photo gallery.

I'm not sure whether I made myself clear, forgive my poor english again....