The footer is made of 3 areas editable in the Appearance->Widgets section.
In the demo site we’ve added a list of our social networking handles by adding the “Connect Widget” and filling in each profile in Footer 1.
In Footer 2 we’ve placed a Twitter Hashtag button. You can do that by adding a “Text” Widget then head to https://dev.twitter.com/web/tweet-button and fill in your details. Then copy the code and paste it in the widget.
In Footer 3 we’ve added a LinkedIn button. We’ve again used a text widget and got our code from https://developer.linkedin.com/plugins/share-plugin-generator
You can choose whatever you prefer, Facebook Like or a Newsletter link.