Yammer App for SharePoint

If your organization has a Yammer network, you can use the Yammer App for SharePoint to add a Yammer feed to your SharePoint site. That way people can post, reply, and like Yammer conversations right inside of team and project websites.
The Yammer App for SharePoint allows you to add a real-time social layer to your SharePoint environment. You can engage in team and company-wide conversations, collaborate around files and projects, and become more productive by using Yammer and SharePoint together. This will help you make collaboration a more social, mobile, and engaging experience.
Moreover, The Yammer App for SharePoint is free. You just need to add the app to your SharePoint.
Get the app here
Setup the app Yammer App for SharePoint: Add a Yammer feed to a SharePoint page