There are endless social media plugins to post the current post to whatever social media network you want and there are endless plugins to add social media sharing buttons to your post as well.
But what I want to do is to be able to share "old" post. Old post meaning post other than the current one being published without having to manually click on each post and click a share button for each network (Facebook, Twitter, Goolge+)
It works like this:
Every X Hours/Days/Weeks a post is selected at random and posted to Facebook (page or profile or both), Twitter and Google+ (personal, business page or both). The plugin should keep track of which post its shared so it doesn't post the same one twice. It should continue to post things at the designated time until it runs out of post.
Once it runs out of post, it should wait until there is a queue of post to be shared (the number of post to wait before starting to random share again should be a user setting).