advanced iframe pro is the most advanced iframe plugin for WordPress and also available as a standalone version.

Advanced iFrame Pro Plugin WordPress Features:
Hide areas of the parent to give the iframe more space
Show only specific areas of the iframe when the iframe is on a same domain
Forward parameters to the iframe Resize the iframe to the content height or width on loading, AJAX or click
Scroll the parent to the top when the iframe is loaded
Hide the content until it is fully loaded
Add a css and js file to the parent page
Security code
Many additional cool features are available the pro version
Show only specifiy areas of the iframe
Zoom iframe content
Modify css styles
Lazy load
Loading indicator
Responsive iframes/videos
Browser detection
Change link targets and show iframes as layer with header/footer
Scrolling on ipad and iphone