I noticed that there are some sites which entice the users to share pre-loaded posts about their company, be it through Twitter, Facebook, Google+, etc. For instance, maybe to unlock some advanced features, the post may ask users to tweet about the topic. The user clicks on a link and a Twitter post is pre-populated with the message that the user can send.

Is the a standard software package that provides this functionality across multiple social platforms, or would a developer have to code this functionality based on each specific API?