Developers respect privacy and permissions guidelines by only requesting those ABSOLUTELY NECCESARY when installing. No full Website data request on install. Read only permissions by default.
Friendly side-bar interface automatically groups your tabs by host/path. A no-brainer add-on for Devs, hackers, and the casual internet user. Thank you, piro_or.

Simply amazing. I love how customisable it is!

非常nice

Wow. This thing is seriously awesome. Why this is not how ALL browers are by default is baffling.

Edit: And it turns out to be better at navigating and managing bookmarks better than the actual bookmark manager.

This is the only way that I use firefox now. I've even edited my chrome to hide the top tabs. Honestly I cannot say enough nice things about this extension and I am thankful it exists.