Useful Firefox Extensions

Tree Style Tab by Piro (piro_or) organizes tabs in a hierarchical tree
Firefox Multi-Account Containers by Mozilla Firefox separate websites from each other to allow multiple logins and limit tracking
DeepL Translate: Reading & writing translator by DeepL an ai powered translator
Grammar and Spell Checker - LanguageTool by LanguageTooler GmbH an ai powered spell and grammer checker
KeePassXC-Browser by KeePassXC Team auto-fills passwords from KeePassXC
Video DownloadHelper von mig, Paul Rouget downloads videos to watch them later on offline
DownThemAll! von Nils Maier mass downloads files from a website, e.g. bank statements