Chromed Bird is an awesome Twitter extension for Google Chrome with lots of features.
Some of the current features are:
* [new] See all your tweets in an unified timeline;
* Follow your timelines (including @mentions, lists, DMs and favorites) and navigate through your tweets;
* Compose, reply, RT, share, favorite and delete tweets;
* Create short URLs within the extension;
* [new] Preview shortened URLs before clicking them;
* Track read / unread tweets;
* Notify user whenever new tweets arrive;
* Tweets caching to avoid hitting Twitter's API rate limit;