Salesforce’s Chatter is an enterprise social network for collaboration between employees. It connects every employee with the files and data they need anytime, anywhere. Chatter enables its users to share files, form groups, share questions & answers and create direct polls. To promote user engagement, it offers contribution scoring, badges, endorsements with highlighting top influencers and contributors to your social network. Other features include profile, status updates, and activity feeds. It is available for Android and iOS mobile application. For free version, CRM purchase is necessary.