From original addon:

"This extension will cycle through all open tabs. If tab contains a single image, the image will be saved to disk and, optionally, the tab will be closed. This is very useful if you view picture galleries and click on various thumbnails to load the full images into separate tabs. With one click you can save all the images, close the tabs they're on, and continue viewing the gallery."

Please Note: Some features from the last addons are not possible because of the nature of the current WebExtensions-technology. Following features are currently not possible to implement:

Custom download folders outside browser's default download location. Folders can only be created inside browser's default download location.
Check if image has already been downloaded. WebExtensions are unable to access file system and check if image is already downloaded.

Original addons: Konbu: https://addons.mozilla.org/en-US/firefox/addon/bazzacuda-image-saver-plus/ Bazza!: https://addons.mozilla.org/en-US/firefox/addon/bazzacuda-image-saver/ Permission descriptions:

Access your data for all websites: When image saving is activated, the addon will access to the web page and tries to find images from it.
Download files and read and modify the browser’s download history: When images are found, they will be added to download queue.
Access browser tabs: When image saving is activated, the addon will access current window's loaded and non-pinned tabs, looking for images to save.
Display notifications to you: Some information and errors are shown as notifications.

Developer response