Freika

<p>This plugin allows to change opacity of all  elements on page to 0.1. This may be useful if your site contain NSFW(Not Safe For Work) images and you do not want make your visitors close this site. Just place NSFW button anywhere you wish or use build-in button(left-bottom).</p>


NSFW WP Images

NSFW WP Images plugin. Allows (almost) hide images on any page.

zingming

<p>When you compose a post, wrap the NSFW content in <code>[nsfw][/nsfw]</code> to hide it. Readers can click on the “Show” link to read the hidden content.</p>


NSFW (Not Safe For Work)

Wrap the NSFW content in [nsfw][/nsfw] to hide it. Readers can click on the "Show" link to read the hidden content.

NSFW WP Images vs NSFW (Not Safe For Work)