・Utility
Gesturefy
https://addons.mozilla.org/ja/firefox/addon/gesturefy/
Tree Style Tab - ツリー型タブ
https://addons.mozilla.org/ja/firefox/addon/tree-style-tab/
OneTab
https://addons.mozilla.org/ja/firefox/addon/onetab/
Tab Session Manage
https://addons.mozilla.org/ja/firefox/addon/tab-session-manager/
FoxyTab
https://addons.mozilla.org/ja/firefox/addon/foxytab/
Auto Tab Discard
https://addons.mozilla.org/ja/firefox/addon/auto-tab-discard/
Enhancer for YouTube
https://addons.mozilla.org/ja/firefox/addon/enhancer-for-youtube/
Flagfox
https://addons.mozilla.org/ja/firefox/addon/flagfox/
Web Archives
https://addons.mozilla.org/ja/firefox/addon/view-page-archive/
Dark Reader
https://addons.mozilla.org/ja/firefox/addon/darkreader/

・Add Search Engine
Search by Image
https://addons.mozilla.org/ja/firefox/addon/search_by_image/
DuckDuckGo Privacy Essentials
https://addons.mozilla.org/ja/firefox/addon/duckduckgo-for-firefox/
Startpage — Private Search Engine
https://addons.mozilla.org/ja/firefox/addon/startpage-private-search/
Feneas Searx
https://addons.mozilla.org/ja/firefox/addon/feneas-searx/

・RSS reader & Web Pages Updates Monitors
Feedbro
https://addons.mozilla.org/ja/firefox/addon/feedbroreader/
FeedBro RSS Japanese language（Feedbro日本語化）
https://github.com/ktkr3d/feedbro-locale
Update Scanner
https://addons.mozilla.org/ja/firefox/addon/update-scanner/

・UserScript Manager
Greasemonkey
https://addons.mozilla.org/ja/firefox/addon/greasemonkey/
Tampermonkey
https://addons.mozilla.org/ja/firefox/addon/tampermonkey/