I've been using BID for about 7 years and cannot fault it. Frequent updates, great support, works seamlessly.

The add-on works well with the installed application.
The application (not the add-0n) has a few shortcomings but I still paid for it and paid to renew.

Having all my freebie downloaders fail at forum galleries, I gave in and downloaded the BID program and the Firefox add-on. I didn't like the idea of external software but it turns out to be seemless. The free trial version has limits, only 2 items/pages queued at a time, 100 images max per gallery, but that's fine for my needs. The nagging is only a banner at the top of the window, come on snowflakes. I got version 5.58, turned on the add-on, clicked the BID button when on a gallery page, and it runs the BID programs to download or queue. The options are vast, and it has performed perfectly every time, automatically creating folders for different galleries & numbering images. Hard to use, nope... click, make a cup of tea, return to completed downloads, it really is that good.

PS. Been using it for a while now, nagging to register (pay) is getting very in your face intrusive, BUT still excelent software.

Using it (the main app i mean) with regular license from year. It's the best in this field and value all the money. Update frequently of the main app ... i remove one star only for this addon because i'm waiting from 2 years that you add a way to customize the shortcut ... in some languages the default shortcut are already in use by firefox itself ... i'm unable to use the ALT-SHIFT-C for example. Please add the way to customize the shortcut and you gain the last star ! :)