Change the background image of the BODY-Tag. A pool of images from Media Library and / or a NextGEN gallery can be used.

Ryan Novotny

Particle Background WP

Particle Backgrounds WP lets you easily add cool particle-style backgrounds to any page.

Premanshu

swapnild

Particle WordPress Backgrounds

Particle WordPress Backgrounds is fast, fully customizable WordPress plugin for adding particle JS effects to the background of websites.

Travis Smith

Genesis Custom Backgrounds

This plugin provides the option to select a default custom background.

Joe Rhoney

AddFunc

AddFunc Backgrounds

Create backgrounds as a content type. Select your backgrounds for any page. Many options and multiple layers available with only a few clicks.

UnderWordPressure

Cosimo is the acronym for “Change Of Scene Image Many Often”. Static background images are boring very quickly. Cosimo wants to avoid this. 
Users of <a href="https://wordpress.org/extend/plugins/nextgen-gallery/" rel="ugc">NextGEN gallery</a> can prepare a gallery of wallpapers and use them on Cosimo settings. 
A string in the glob-style format, for example, *69*Summer, Spring?-Break*, etc. can also select images from the media library. 
The change interval may following a number of page views or time (minutes, hours, days, weeks, months, years done). 
The background image is used on the site about inline CSS, as in this example:
<blockquote>
body {background-image:url(http://…../wp-content/uploads/bg-superduper.jpg) !important;} 
 Cache tools such as <a href="https://wordpress.org/extend/plugins/wp-super-cache/" rel="ugc">WP Super Cache</a> can cause additional delays, especially in the range of hours. If necessary, the plugin could be expanded to also change the Header image. User feedback is welcome.
</blockquote>

Alternatives to Cosimo – Change Of Scene Image Many Often

Top alternatives