Marko Heijnen

CodeKitchen

At this moment it only adds a gallery endpoint to posts with only one theme. In the next couple of weeks I will be looking at more solutions and build themes around those. I will then also start building a settings page where you can select what the default theme is and build a metabox where you can select per post what the options should be.
A demo can be seen at https://fesere.de/. If you go to https://fesere.de/african-wildlife/ you see it’s a gallery provided by the theme and gets extended by this plugin. So when you go to https://fesere.de/african-wildlife/?fullscreen you see the same images but without the rest of the site. The plugin is so build that it should easily integrate in your existing theme.

Fullscreen Gallery

A simple plugin that adds a fullscreen endpoint to display the gallery images

Scott DeLuzio

AMP-MODE

Simple Full Screen Background Image will allow you to easily upload and set a full screen image as the background of your website. Images will be automatically scaled with the browser, so regardless of the browser size, the image will always fill the screen, even as the browser is resized live.
Once activated, go to Appearance > Fullscreen BG Image. From here click Choose Image, then either upload from your computer or choose one from the media library. Once you have chosen your image, select the size you wish to insert and click Insert Into Post. A preview of your image will appear below. Now click Save Options 
and view your site. The image should now be applied as a full screen background image.
<h4>Go Pro!</h4>
A greatly enhanced Pro version is <a href="https://fullscreenbackgroundimages.com/downloads/full-screen-background-images-pro/" rel="nofollow ugc">available</a>! Features of the pro version include:
<ul>
<li>Unlimited background images</li>
<li>Post / page-specific background images</li>
<li>Multiple images with fade transitions on pages</li>
</ul>
Learn more about the Pro version <a href="https://fullscreenbackgroundimages.com/downloads/full-screen-background-images-pro/" rel="nofollow ugc">here</a>.

Simple Full Screen Background Image

This plugin provides a simple way to set an automatically scaled full screen background image.

Fullscreen Gallery vs Simple Full Screen Background Image