Via shortcode, lets you call in a list of posts that are filtered, ordered, and displayed based on criteria you provide.
This plugin is useful if you are using lots of posts in a variety of ways on your website, i.e. not just on your homepage and not just separated out by categories. For example, You may have a blog with lots of information on upcoming events and lots of announcements. You have a variety of people who come to your blog looking for different information, and it's hard for them to filter through everything. You can have a "Cats" page on which you talk about your stance on cats, and use
[ahs_callposts] to also call in a list of posts in the "cats" category, perhaps only the most recent 10, perhaps just titles, perhaps displaying just excerpts, perhaps displaying an image for each post. Then have a separate page for the "dogs" category. Etc!