DownloadThemAll add-on, which lets you download links or images on a webpage in Firefox browser has (major) version 3 released –DownThemAll 3.0.2 – is available on AMO with e10s support and is compatible with Firefox 45-50. This version’s development has taken a lot of time as the first beta was released in 2013, with Per-Windows private browsing and HiDPI support.
READ: DownThemAll 3.0 Beta adds Support for HiDPI and Per-window Private browsing
DownThemAll version 3 interface
During the version 3 development phase, when Mozilla announced about signature requirement and deprecation of XUL-based add-ons, the developer said the DownThemAll add-on was almost dead. But despite all that, we’ve now a new version available with improved interface, including full Australis support, and is a restartless add-on now.

You can find the complete changelog for this version on AMO here.
READ: 3 Firefox Extensions to Download/Save All the Images on a Webpage