TweetDeck gives the Twitter experience more flexibility by letting you view multiple timelines in one easy interface. It includes a host of features to help advanced users get the most of Twitter: manage multiple Twitter accounts, schedule Tweets for posting in the future, build Tweet collections and more.
Tweeting from multiple accounts - TweetDeck allows you to tweet from multiple accounts easily.
Favoriting from multiple accounts - TweetDeck allows you to favorite a Tweet from multiple accounts.
Following from multiple accounts - TweetDeck allows you to follow a user from multiple accounts, all at once. You can also follow a user by clicking follow on their profile, but only your default account will follow them.