I tried this as a replacement for DownThem All, and it turned out to be even better than that Add on. It is a paid app and additional downloading is required, but it's so smart in how it gathers all the highest resolution images from a site. Free version works just fine, but if you want to download batches of hundreds of images, you'll need the paid version.

the last version break compatibility with old BID version.... that force me to buy the lastest version...
(problem because installed automatically by firefox....)