One of the basic building blocks of a functioning publishing tool is the ability to view, edit, and preview content before it's published. In older versions of Drupal, that was an all-or-nothing affair: either you gave people the dangerously overpowered "Administer Content" permission, or you downloaded a comprehensive access control module and started building a custom permissions system of your own. In Drupal 7, it improved: roles can be given permission to view their own unpublished content, or given the ability to bypass all content access control, but it's still a bit clunky for a lot of very common use cases. Thankfully, there's the aptly-named View Unpublished module. It brings juuuuust enough control without requiring a complex permission matrix.
Once you've installed View Unpublished, a set of new permissions becomes available. You can grant individual roles the ability to view other users' unpublished content on a per-content-type basis. With that one addition, it becomes much easier to build simple editorial dashboards that give editors or contributors limited access to other writers' work before publishing, or for all the members of a team to see what the site will look like once content goes live.
Normally, we'd include a screenshot of the module 'in action,' but the simplicity of the tool makes that a bit tough. When View Unpublished is working, most users don't see anything at all! There are a few limitations to the module's streamlined approach, of course. Permission to publish and unpublish content is still handled by other tools, and it's up to you or another site builder to construct a functional "dashboard" for unpublished content if it isn't already listed on the front page or another easy-to-find location. For quick and simple access permissions on limited publishing workflows, however, View Unpublished is a great tool.