Rafael Paulino

With this plugin you can place an iframe inside the TinyMCE text editor. 
You click a button in TinyMCE and a window appears to place the iframe data. 
Then just click on Ok and a shortcode is inserted with the iframe data and on the front the iframe is presented.
Com este plugin você consegue colocar um iframe dentro do editor de texto TinyMCE. 
Voce clica em um botão no TinyMCE e aparece uma janela para colocar os dados do iframe. 
Depois é só clicar em Ok e um shortcode é inserido com os dados do iframe e no front é apresentado o iframe.

Rafa TinyMCE Iframe

With this plugin you can place an iframe inside the TinyMCE text editor.

dbhynds

Lazy load images, YouTube and Vimeo videos, and iframes using <a href="https://github.com/ressio/lazy-load-xt" rel="nofollow ugc">Lazy Load XT</a>.
Lazy Load XT is the fastest, lightest, fully customizable lazy load plugin in the WordPress Plugin Directory.
This plugin works by loading the Lazy Load XT script and replacing the <code>src</code> attributes with <code>data-src</code> when the content of a post or page is loaded on the front end of a WordPress site.

Lazy Load XT

See this image
http://i.imgur.com/PzOIDGI.png
It's my main page's slider, it loads blank when installing this plugin
When the page loads at the first time without any cache, it loads with the browser's default font, then suddenly changed into the site's font. Not just the images in "not seen parts", but also images in the view port load blank. I would say this plugin has a huge potential, but at the moment, as it's not updated, it doesn't function as it advertises despite having 5/5 reviews.



Not really impressive as I thought

Lazy Load images, videos, iframes and more using Lazy Load XT.

Rafa TinyMCE Iframe vs Lazy Load XT