Enterprise social network Yammer has launched a new open-source mobile SDK so developers can build Yammer features into iOS and Windows Phone 8 apps.

This move gives more leeway to enterprise developers wanting to make their apps social — or at least to make their mobile apps work nicely with one of the most popular enterprise communication tools around.

The core functionality and features of Yammer have not changed drastically since it was purchased by Microsoft for $1.2 billion in July 2012. Still, Yammer has continued to implement small changes and give the platform more stability.

Today’s mobile SDK launch shows yet another slight move. But this one implies that Microsoft not only wants Yammer to function well on its own but also wants its functionality to be integrated with other enterprise-focused apps.

Microsoft especially seems keen on making Yammer the go-to service for social activity in enterprise apps rather than leave any room for competitors such as Jive, Salesforce’s Chatter, or Tibco’s Tibbr. The company writes in a blog post today:

Here at Yammer Engineering, we believe in keeping a quick pace. This is evident in the Yammer Platform, where developers can rapidly build social enterprise apps. Apps that can scale to Fortune 500-sized companies. To speed up the app development process, we are releasing Open Source SDKs for iOS and Windows Phone 8.

The SDKs enable you to add Yammer OAuth 2-based authentication to your smartphone and tablet apps. Once authenticated, you can use the SDKs to make REST calls to read/write from the Yammer API, thus integrating the full spectrum of Yammer’s social services into your mobile app.