Diana K. Cury

List post from a specific category with options like date format, link text, order and more. Locus is a very simple plugin for display content in diferrent ways:
<ul>
<li>Display a single post, page or any available post type.</li>
<li>Display full content or the excerpt, or both!</li>
<li>Category descriptions are visible by default, if any.</li>
<li>Configure date format, link text or hide them all.</li>
<li>Use styles for every block, (refer the stylesheet in <code>locus/control/locus-style.css</code>)</li>
<li>Set display post orders, such random, by date, by author, comment count (popularity) etc</li>
<li>Display thumbnails, if available</li>
<li>Easy to use: you don’t have to learn to use it</li>
<li>Settings per widget, so you can have different widgets.</li>
</ul>

Locus

Locus allows you display any post, page or post type in widgetized areas of you site.

Amaury Balmer

Nicolas Juen

This plugin allow to build relation between 2 custom types (posts, page, custom), very useful for manage related content on CMS type website.
A few example use cases:
<ul>
<li>manually lists of related posts</li>
<li>post series</li>
<li>rented houses connected to agency</li>
<li>etc.</li>
</ul>
Relationships are created from a settings page from the administration console.
This plugin can not do relationships with users, you should test this excellent plugin made by scribu 
https://wordpress.org/extend/plugins/posts-to-posts/

Relations Post Types

This plugin allow to build relation between 2 custom types (posts, page, custom), very useful for manage related content on CMS type website.

Locus vs Relations Post Types