One year ago, social developer Playdom created the MySpace mafia RPG known as Mobsters, and in the span of about three months it became the top game on the network. Today it holds that #1 spot with over 13.5 million installs. Earlier this summer, the game was released on Facebook, where it’s already grown to over 1 million monthly active users. Now, Playdom is bringing the game to the iPhone.

The new Mobsters Big Apple for iPhone keeps all the classic game mechanics many players have come to know and love. Users can run missions, earn cash and experience, build up arsenals, purchase real estate, and, yes, they can still pick fights with other mobs.

However, the iPhone version of the game will also sport some brand new features, including new missions from the “Mysterious Mr. X” as well as missions for up to 30 “hired guns.” Best of all, however, is that users of the iPhone title will not have to start all over from scratch. Users can connect their Mobsters game to their MySpace instance of the game, so players can check those criminal assets at anytime, from anywhere. (Facebook Connect support is coming soon.)

Time will tell whether Mobsters Big Apple will become the biggest mafia game on the iPhone. Zynga’s own Mafia Wars has been sitting pretty on the phone for some time now (not to mention similar mafia RPG clones), and they’re sure to put up a fight. Nevertheless, Mobsters game has been hanging tough on MySpace for the greater part of a year, so there are sure to be interesting battles for #1 in the months ahead.