Google has released many official Chrome extensions for its brand new social networking website, the Google+. There are extensions like Google +1 Button and Google+ Notifications along with several other unofficial extensions.
Unfortunately, there is no browser extension for other browsers from Google+ team. Google+ does not offer even a bookmarklet for the users of Firefox, Opera and Internet Explorer. This is very disappointing, as the existing extensions created by independent developers are not so attractive.

There may be some valid reasons behind this, but this seems intentional as there is no browser extension by Google for its other services as well. Google offers browser extensions only for Chrome. There are tons of extensions by Google team in the Chrome Web Store for many Google services like Google Docs, Picasa, Gmail, Calendar and even Orkut, but not a single extension for the users of other browsers. Moreover, Google has discontinued their toolbar add-on for Mozilla Firefox. This is sad.
Thanks, independent developers!