Demonstrations:

Are over here: http://mintchaos.github.io/flippant.js/

Whys and hows:

• Flippant is tiny. It does just enough and no more. It has zero dependencies.
• Flippant is easily customized. A couple of arguments, and CSS.
• Flippant has a single function: flippant.flip. Use it to flip things!

var front = document.getElementById('flipthis')
  , back_content = "<h1>I'm the back!</h1>" // Generate or pull any HTML you want for the back.
  , back

// when the correct action happens, call flip!
back = flippant.flip(front, back_content)
// this creates the back element, sizes it and flips it around.

// call the close method on the back element when it's time to close.
back.close()
// alternatively you can trigger a close event on the back element if you fancy.
var close_event = new CustomEvent('close')
back.dispatchEvent(close_event)

Two modes: card (the default), and modal.

back = flippant.flip(front, back_content, 'modal')

The back gets the default class of flippant-modal-dark for modal flips and flippant-modal-light for cards. These styles can be overriden or you can pass in your own class.

back = flippant.flip(front, back_content, 'modal', 'my-modal-classname')

The full API:

flip(element_to_flip, content_for_back, type(modal/card), classname_for_back) -> back_element

74.3% of the magic is in the css file. Override however you'd like.

“Installation”

Grab the JS and the CSS file. Use them. The JS file is a UMD package so require or commonjs it or just use it. It's not picky.