Add sidebars and widgets above below and in the content
Sidebars and widgets are a great feature of WordPress as they enable the user to add persistent content in all (or just big set of) pages of the site, without having to write any code. The only problem, is that the locations in which it is actually possible to do (Also Known As sidebars, even when they are horizontal) are predefined by the theme and luck flexibility.
This plugin adds two widgetized areas, above and below the content, enabling the user to add widgets like search, email subscription, general banners, just where they will be best placed to attract the attention of the reader without a need to modify the content or the code.
In addition a shortcode can be used to to define sidebars in the content itself, enabling you to do things like dynamically decide where to place the same ads or call to action in the content, in several different pages, post, or any other content.
You might need to do some one time CSS modification to adjust the styling of the sidebar and widgets to the theme, best done by modifying your theme files, but can also be done with any plugin that lets you add costume CSS if the site is in a network setting.