A complete ImageFap.com gallery conversion script featuring customization options and multiple viewing modes. Original author is Ryan Thaut, but it looks like abandoned.
Update: script uses some outdated code which is not compatible with Greasemonkey. I tried with Tampermonkey and the script does work, but only in slideshow mode. As another user said, in scrolling mode all the pictures are stacked on top of one another. Unfortunately, in slideshow mode the images are tiny so this script is not really useful anymore without some needed updates.
Original gallery flashes on the screen for a split second, then entire window turns white and I see no content at all :(