Last July, OpenFeint, a mobile social gaming platform, launched a newsfeed service called GameFeed that teases gamers with the accomplishments of their friends.  GameFeed is inherently social and also competitive, posting running leaderboards for all to see, and allowing gamers using different mobile platforms to compete against one another.  OpenFeint is now releasing an SDK for GameFeed, further extending the reach of this game-centric activity stream.

With the new GameFeed SDK, developers can expose their games’ community through a new drop-in widget with one line of code.  Players see a stream of in-game updates based on the activity of other players in the OpenFeint network.  By immediately seeing when a friend has bested a high score or unlocked a seemingly unattainable achievement, players are encouraged to play with each other more frequently.

For players who opt in to OpenFeint, GameFeed will soon introduce them to new gamers, intelligently suggesting new friendships, featuring interesting changes to user profiles, and recommending new games that are popular among friends.

By adding the GameFeed plugin, OpenFeint claims that during beta tests with 24 people, GameFeed increased sessions-per-user by 25 percent, and that some developers are experiencing a 60 percent in sessions-per-user.

“OpenFeint is committed to delivering a next generation social network with features that will help free-to-play games improve lifetime value,” said Jason Citron, founder and CEO of OpenFeint. “Sessions per user is a key engagement component of lifetime value and GameFeed significantly increases engagement at no additional cost to developers.”

With news of the SDK, several top publishers are joining GameFeed. Big Blue Bubble (makers of Burn the Rope), Get Set Games (makers of Mega Jump), PikPok (makers of the Flick Kick series) and Sibblingz (publishers of Island Tycoon) are launch partners for the new integration. OpenFeint has been a largely influential platform in expanding gaming capabilities and social interactions beyond a given mobile OS, and the GameFeed SDK makes it more competitive with the likes of Facebook, and even Apple and Google+.

Apple’s iOS has something similar in its portfolio called Game Center — attractive but underutilized.  This is also used by developers to tell other users about their friends or competitors’ scores in a game. With the introduction of iOS 5, there will be support for turn-based games, with push notifications for the opponents when it’s their turn to play.  But it’s still limited to iOS games. PlayHaven also had a platform-busting release this week, for the mobile advertising sector.  Its new real-time marketing tools help developers get deeper interaction access with gamers and app users, even on iOS, freeing a great deal for publishers.