Edit in JSFiddle


              
<nav>
    <ul class="panel">
        <li class="color-1"> <a href="#">
                <div class="front">
                    <i class="fa fa-home fa-4x"></i>
                </div>
                <div class="back">
                    <span>HOME</span>
                </div>
            </a>

        </li>
        <li class="color-2"> <a href="#">
                <div class="front">
                    <i class="fa fa-align-left fa-4x"></i>
                </div>
                <div class="back">
                    <span>BLOG</span>
                </div>
            </a>

        </li>
        <li class="color-3"> <a href="#">
                <div class="front">
                    <i class="fa fa-camera-retro fa-4x"></i>
                </div>
                <div class="back">
                    <span>PORTFOLIO</span>
                </div>
            </a>

        </li>
        <li class="color-4"> <a href="#">
                <div class="front">
                    <i class="fa fa-user fa-4x"></i>
                </div>
                <div class="back">
                    <span>ABOUT ME</span>
                </div>
            </a>

        </li>
        <li class="color-5"> <a href="#">
                <div class="front">
                    <i class="fa fa-comments fa-4x"></i>
                </div>
                <div class="back">
                    <span>CONTACT</span>
                </div>
            </a>

        </li>
    </ul>
</nav>
@import url(http://fonts.googleapis.com/css?family=Roboto:400,100,300,500,700,900);
@import url(http://netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css);

nav ul {
  min-width: 600px;
  position: relative;
  display: table;
  margin: 50px auto;
  clear: both;
}

nav ul li {
  list-style: none;
  float: left;
}

nav ul li a {
    width: 100px;
    height: 100px;
    float: left;
    margin: 0 10px;
  -webkit-perspective: 600px;
     -moz-perspective: 600px;
      -ms-perspective: 600px;
          perspective: 600px;
}

nav ul li .front {
  text-align: center;
  -webkit-transform: rotateX(0deg) rotateY(0deg);
     -moz-transform: rotateX(0deg) rotateY(0deg);
      -ms-transform: rotateX(0deg) rotateY(0deg);
       -o-transform: rotateX(0deg) rotateY(0deg);
  -webkit-transition: all 0.5s ease-in-out;
     -moz-transition: all 0.5s ease-in-out;
      -ms-transition: all 0.5s ease-in-out;
       -o-transition: all 0.5s ease-in-out;
          transition: all 0.5s ease-in-out;
  -webkit-backface-visibility: hidden;
     -moz-backface-visibility: hidden;
      -ms-backface-visibility: hidden;
       -o-backface-visibility: hidden;
          backface-visibility: hidden;
  -webkit-transform-style: preserve-3d;
     -moz-transform-style: preserve-3d;
       -o-transform-style: preserve-3d;
          transform-style: preserve-3d;
}

nav ul li:hover .front {
  -webkit-transform: rotateX(0deg) rotateY(180deg);
     -moz-transform: rotateX(0deg) rotateY(180deg);
      -ms-transform: rotateX(0deg) rotateY(180deg);
       -o-transform: rotateX(0deg) rotateY(180deg);
}

nav ul li .back {
  position: absolute;
  top: 0;
  width: inherit;
  height: inherit;
  text-align: center;
  z-index: -1;
  -webkit-transform: rotateX(0deg) rotateY(-180deg);
     -moz-transform: rotateX(0deg) rotateY(-180deg);
      -ms-transform: rotateX(0deg) rotateY(-180deg);
       -o-transform: rotateX(0deg) rotateY(-180deg);
  -webkit-transition: all 0.5s ease-in-out;
     -moz-transition: all 0.5s ease-in-out;
      -ms-transition: all 0.5s ease-in-out;
       -o-transition: all 0.5s ease-in-out;
          transition: all 0.5s ease-in-out;
  -webkit-backface-visibility: hidden;
     -moz-backface-visibility: hidden;
      -ms-backface-visibility: hidden;
       -o-backface-visibility: hidden;
          backface-visibility: hidden;
  -webkit-transform-style: preserve-3d;
     -moz-transform-style: preserve-3d;
       -o-transform-style: preserve-3d;
          transform-style: preserve-3d;
}

nav ul li:hover .back {
  z-index: 1;
  -webkit-transform: rotateX(0deg) rotateY(0deg);
     -moz-transform: rotateX(0deg) rotateY(0deg);
      -ms-transform: rotateX(0deg) rotateY(0deg);
       -o-transform: rotateX(0deg) rotateY(0deg);
}

nav ul li i {
  line-height: 100px !important;
  color: white;
  vertical-align: middle !important;
}

nav ul li span {
  font-family: 'Roboto';
  font-size: 20px;
  font-weight: 300;
  line-height: 100px;
  color: white;
  text-transform: lowercase;
  vertical-align: middle;
}

nav ul li.color-1 .front,
nav ul li.color-1 .back {
  background-color: #e6567a;
}

nav ul li.color-2 .front,
nav ul li.color-2 .back {
  background-color: #00c0e4;
}

nav ul li.color-3 .front,
nav ul li.color-3 .back {
  background-color: #5bd999;
}

nav ul li.color-4 .front,
nav ul li.color-4 .back {
  background-color: #7658f4;
}

nav ul li.color-5 .front,
nav ul li.color-5 .back {
  background-color: #eac14d;
}