>>190
タブ休止系
Tab Suspender (memory saver)
https://addons.mozilla.org/ja/firefox/addon/tab-suspender-tab-unloader/
(併せて便利な)
HoldTab
https://addons.mozilla.org/ja/firefox/addon/holdtab/

画像保存
Image Picka
https://addons.mozilla.org/ja/firefox/addon/image-picka/
[BETA] Double-click Image Downloader
https://addons.mozilla.org/ja/firefox/addon/double-click-image-download/
image-save (インスタ用)
https://addons.mozilla.org/ja/firefox/addon/instagram-save/