Zynga is rolling out a number of social and usability improvements in mega-hit Draw Something.

As of today, users can post their drawings to Facebook and Twitter, undo mistakes, refresh drawings and complete successful streaks of up to 999 rounds. Several of the new features were on developer OMGPOP’s wish list before Zynga bought the company for $180 million in March.

Zynga also has greatly improved the game’s social features. Players can now send each other short messages of up to 100 characters that are attached to drawings. Players can respond after they guess their partner’s drawing. These additions put Draw Something in line with Zynga’s With Friends franchise of games, and fit in nicely with Zynga’s “connecting the world through games” mission statement.

Since its release in February, Draw Something has seen nothing but the top of the rankings charts. On Android the app is the No. 1 paid app, the No. 15 free app and the No. 6 top grossing app.

On iOS the free version of the game holds the No. 5 spot on free iPhone app charts and the No. 3 spot on the free iPad app charts. It is also the No. 28 top grossing iPhone app and the No. 71 top grossing iPad app. The $0.99 paid version is the No. 2 paid iPhone app, the No. 2 paid iPad app, as well as the No. 6 top grossing iPhone app and the No. 22 top grossing iPad app.

According to our traffic tracking service AppData, 36.4 million monthly active users and 12.1 million daily active users log into the game using Facebook Connect.