Flagging new discussions in a community

Has anyone had any luck with being able to show a flag indicating there are new discussions on a forum.  We are trying to increase user uptake on one of our discussion forums, but their biggest complaint is that they don't know a new discussion or post has been added and don't think to check the community without that flag.  I know we can set up alerts via email, but it clogs up their email and is not the solution we are looking for. 

Ideally we would like the button/link on the home page to indicate that a new post has been added - similar to how new emails are flagged.