Firefox is one of the best browsers out there. It is developed by Mozilla whose mission is to promote openness, innovation and opportunity on the web.
The main advantage of using firefox is its wide range of extensions. some are most powerful and expands a lot of functionality.
Most popular addons in recent times are Adblock Plus, Firebug, Ghostry. Now firefox includes sync which syncs bookmarks, history, opened tabs, stored passwords across all devices. The Android version of firefox looks and feel the same as desktop version. You can even protect your passwords using Master password. By using addon Master Password+ you can password protect firefox. Firefox provides customizable interface which is unique to firefox. It has the best security protocols. Iam using firefox for 15years and iam a big fan of it. I use other browsers too.